阅读说明：本技术 离子源和方法 (Ion source and method ) 是由 T·韦克塞尔 于 2021-05-26 设计创作，主要内容包括：根据不同的实施方式,离子源(100)可以包括：多个电极,该多个电极彼此电分离地安装并且包括：第一电极(102a),第一电极具有凹陷部(106),第二电极(102b),第二电极设置在凹陷部(106)中,第三电极(102c),第三电极部分地覆盖凹陷部(106)并且间隙(108)穿过第三电极,间隙暴露第二电极(102b)；一个或多于一个的磁体(104),磁体设计用于在间隙(108)中提供磁场。(According to various embodiments, an ion source (100) may include: a plurality of electrodes mounted electrically separated from each other and including: a first electrode (102a) having a recess (106), a second electrode (102b) disposed in the recess (106), a third electrode (102c) partially covering the recess (106) and through which passes a gap (108) exposing the second electrode (102 b); one or more magnets (104) designed to provide a magnetic field in the gap (108).)

1. An ion source (100), comprising:

a plurality of electrodes mounted electrically separated from each other and comprising:

a first electrode (102a) comprising a recess (106);

a second electrode (102b) disposed in the recess (106);

a third electrode (102c) partially covering the recess (106) and through which a gap (108) passes exposing the second electrode (102 b);

one or more magnets (104) designed to: a magnetic field is provided in the gap (108).

2. The ion source (100) of claim 1, further comprising:

a first dielectric holding structure (202a) that holds the second electrode (102b) and electrically separates the second electrode from the first electrode (102 a); and

a second dielectric holding structure (202b) that holds the third electrode (102c) and electrically separates the third electrode from the first electrode (102 a).

3. The ion source (100) of claim 1 or 2, wherein the third electrode (102c) has a first plate-shaped section (302) and a second plate-shaped section (304), the gap (108) being formed between the first plate-shaped section and the second plate-shaped section.

4. The ion source (100) according to any of claims 1 to 3, wherein the first electrode (102a) is designed as a slot.

5. The ion source (100) of any of claims 1 to 4, wherein the gap (108) extends along a closed path.

6. The ion source (100) of any of claims 1 to 5, further comprising:

a fourth electrode (102d) through which an additional gap passes;

wherein the gap (108) is arranged between the additional gap (108) and the second electrode (102 b).

7. The ion source (100) of claim 6, wherein the additional gap (108) is defined on mutually opposite sides by additional faces of the fourth electrode (102d) running obliquely to one another.

8. The ion source (100) of claim 7, wherein a spacing of two of the additional faces from each other substantially corresponds to a spacing between two faces of the third electrode (102c) defining the gap (108) on sides opposite to each other.

9. A method (1200) for operating an ion source (100) according to any of claims 1 to 8, the method comprising:

applying a first voltage to the second electrode (102b) and the third electrode (102 c); and

applying a second voltage to the first electrode (102a), the second voltage being different from the first voltage.

10. A method (1300) for operating the ion source (100) according to any of claims 1 to 8, the method comprising:

applying a first voltage at the third electrode (102 b); and

applying a second voltage to the second electrode (102b) and the first electrode (102a), the second voltage being different from the first voltage.

Technical Field

Various embodiments relate to ion sources, methods, control devices, and manipulation apparatus.

Background

In general, the workpiece or substrate may be subjected to processing, such as machining, cladding, heating, etching, and/or texturing. The method for processing the substrate is, for example, ion irradiation. By means of ion irradiation, the substrate can be irradiated, for example, with ions, so that the ions are built into the substrate or material is detached from the substrate. For this purpose, the gas forming the plasma can be ionized between two electrodes, wherein ions for irradiation are extracted from the plasma formed there. The extracted ions may be accelerated towards the substrate with which they ultimately interact.

Plasma formation may be assisted by means of a magnetic field in order to locally increase or concentrate the ionization rate of the gas forming the plasma. For generating the magnetic field, a magnet system can be arranged relative to the electrodes, so that a plasma channel, a so-called track, can be formed in the vicinity of the electrodes, in which plasma can be formed.

Conventionally, a so-called Anode Layer Ion Source or Closed electron Drift Ion Source (ALS) (hereinafter, referred to as "Anode Layer Ion Source", "Closed Drift Ion Source") is used to generate plasma in a magnetic field-enhanced manner for Ion irradiation.

However, in ion source operation, material accumulates at the electrode (referred to as the anode for short) operating as an anode (also referred to as a parasitic coating). Conventionally, generators, converters and/or other ion sources are additionally used (in bipolar operation) to counteract such parasitic coatings. Oxygen is also used to clean the anode. However, oxygen also inhibits the rate of fogging at the substrate.

Disclosure of Invention

It has been recognized according to various embodiments that: these concepts are based on external action on the ion source, requiring additional expense and additional cost. In this context it is recognized that: the ion source may be designed such that it itself suppresses the parasitic coating by: for example by being cleaned itself and/or by counteracting the cause of the parasitic coating.

Thus, according to various embodiments, an ion source, a method, a control device and a manipulation apparatus are provided that suppress this parasitic coating. By way of example, the configuration of the electrodes of the ion source is provided in such a way that complex electric field distributions which suppress parasitic coatings can be generated by means of these electrodes. The electric field distribution (also referred to as a cleaning mode of operation) can be generated, for example, in such a way that the parasitic coating is stripped off again stepwise, so that the amount of material deposited on average decreases over time. For example, the electric field distribution (also referred to as a low ion energy mode of operation) may be generated such that the kinetic energy of the ions is minimized at the point in time of arrival at the substrate, so that a smaller amount of material is derived from the substrate per unit time. The ion source thus provided may have higher durability and/or reduced parasitic coatings, and/or enable irradiation of the substrate with low ion energy such that the substrate is not misted/stripped, and instead only surface activation of the substrate occurs.

Illustratively, the ion source has two electrodes and one or more additional electrodes, for example, electrodes mounted electrically in an insulating manner (also referred to as additional electrodes). The additional electrode makes it possible for the ion source to be operated not only by means of a direct voltage (also referred to as direct voltage mode of operation) but also by means of an alternating voltage (also referred to as alternating voltage mode of operation). The alternating voltage operation mode is realized as follows: ions are emitted once per voltage cycle duration in a direction toward the substrate and are thereafter received once (e.g., in a direction away from the substrate and/or in a direction into the ion source interior) to strip away the parasitic coating (also referred to as a cleaning phase or cathode phase).

Alternatively to the alternating voltage mode of operation, one or more additional electrodes make it possible to provide a more complex electric field profile in the direct voltage mode of operation, which slows down the ions before they reach the substrate. For example, the potential of the electrode operating as an anode may be closer to the potential of the substrate (e.g., ground potential) while the additional electrode above it is at a negative potential (e.g., in the-kV range). Thereby reducing the potential difference between the anode and the substrate (the substrate is for example grounded or has a floating potential). Thus, the kinetic energy of the ions extracted from the emission gap due to acceleration caused by the potential difference between the plasma and the substrate is reduced and may be, for example, in the two-digit eV range.

In this case, reference is made to time-invariant (also called invariable) and time-variable physical variables (for example voltages). Variability or invariance may be understood as being measured in time periods of at least a plurality of cycles of the alternating voltage used to supply the ion source, and/or time periods of at least one second or at least one cycle of the national grid voltage. For example, the ion source may be supplied with a supply voltage in the kHz range such that the time period may have a plurality of cycle durations of at least 1 millisecond (ms).

Drawings

Shown in the attached drawings:

fig. 1 to 11 show different schematic views of an ion source according to different embodiments, respectively;

fig. 12 to 15 show schematic flow diagrams of methods according to different embodiments, respectively;

fig. 16 shows a schematic control diagram of an operating device according to various embodiments;

fig. 17 and 18 show schematic process diagrams of a treatment device according to different embodiments, respectively; and

fig. 19 to 21 show different schematic diagrams of different modes of operation of an ion source according to different embodiments, respectively.

Detailed Description

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as "upper," "lower," "front," "rear," etc., is used with reference to the orientation of the figure(s) being described. Because components of the embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. It is to be understood that the features of the different exemplary embodiments described herein may be combined with each other, as long as they are not specifically stated otherwise. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

Within the scope of this specification, the terms "connected," "coupled," and "coupled" are used to describe direct and indirect connections (e.g., ohmic and/or conductive connections such as conductive connections), direct or indirect couplings, and direct or indirect couplings. In the drawings, identical or similar elements are provided with the same reference numerals, where appropriate.

According to various embodiments, the terms "couple" or "coupling" may be understood to refer to a connection and/or interaction (e.g., mechanical, hydrostatic, thermal, and/or electrical), such as direct or indirect. The plurality of elements may be coupled to each other, for example, along an interaction chain along which interactions (e.g., signals) may be transmitted. For example, two elements coupled to each other may exchange interactions with each other, such as mechanical, hydrostatic, thermal, and/or electrical interactions. According to various embodiments, "coupled" may be understood to mean mechanically (e.g., physically) coupled, e.g., by direct physical contact. The coupling may be arranged to transmit mechanical interaction (e.g. force, torque, etc.).

Control can be understood as the desired effect of the system. The current state (also referred to as the actual state) of the system may change according to a preset (also referred to as the target state). Closed-loop control may be understood as control in which changes in the system state due to disturbances are additionally counteracted. Illustratively, the control may have a forward oriented control path, further illustratively implementing sequential control that converts input variables (e.g., presets) to output variables. However, the control path may also be part of a closed-loop control loop, so that closed-loop control is implemented. In contrast to purely directional sequential control, closed-loop control has a continuous influence of the output variable on the input variable, which is caused (fed back) by a closed-loop control loop. In other words, closed-loop control means may be used instead of or in addition to control means, or closed-loop control may be performed instead of or in addition to control. The state of the system (also referred to as the operating point) may be represented by one or more controlled variables of the system, the actual values of which represent the actual state of the system and the target values (also referred to as set points) of which represent the target state of the system. In closed-loop control, the actual state of the system (determined, for example, on the basis of measurements) is compared with a target state of the system, and one or more controlled variables are influenced by means of corresponding manipulated variables (using control elements) in such a way that deviations of the actual state of the system from the target state are minimized.

Electrically conductive is understood herein to have a composition of greater than about 1 siemens per meter (S/m), for exampleGreater than about 10³S/m or greater than about 10⁵Conductivity of S/m. Electrical insulation may be understood herein to have less than about 10^-6Siemens per meter (S/m), e.g. less than about 10^-8S/m of less than about 10^-10S/m or less than about 10^-12The electrical conductivity of (1).

The magnet may comprise a magnetized material having a magnetization and may be exemplarily designed as a permanent magnet. The magnet may for example have or be formed from a hard magnetic material. Illustratively, the hard magnetic material may have a high coercive field strength, e.g., about 10³Amperes per meter (A/m) or higher, e.g. about 10⁴A/m or higher, e.g. about 10⁵A/m or higher. Examples of hard magnetic materials include: rare earth compounds (e.g., neodymium iron boron (NdFeB) or samarium cobalt (SmCo)), hard magnetic ferrites, benzyl alcohol, and/or alnico.

A magnetizable (e.g. ferromagnetic) material may be understood as a soft magnetic material, which is illustratively easily repeatedly magnetizable, i.e. which has an exemplary low coercive field strength, for example less than about 10³A/m, for example less than about 100A/m, for example less than about 10A/m. Examples of soft magnetic materials include: iron, soft magnetic ferrite, steel, cobalt, amorphous metal, NiFe compound.

The magnetic (e.g., soft and/or hard) material can comprise, for example, about 10 or more, such as about 100 or more, such as about 10³Or greater, e.g. about 10⁴Or greater, e.g. about 10⁵Or greater permeability.

Non-magnetic materials are understood to be materials which are substantially magnetically neutral, for example materials which are slightly paramagnetic or slightly diamagnetic. The non-magnetic material may comprise, for example, a magnetic permeability of substantially 1, i.e. in the range of about 0.9 to about 1.1. Examples of the nonmagnetic material include: graphite, aluminum, platinum, copper, ceramics (e.g., oxides).

Here, the formation of plasma can be understood as: the atoms of the gas (also referred to as the plasma-forming gas) are ionized. The gas may comprise, for example, an inert gas, i.e. for example argon. The ionizing may include: electrons are extracted from the gas atoms so that positively charged atomic residues (so-called ions) are formed. The plasma has ions and electrons. If the plasma is exposed to an electric field, ions can be separated from electrons (also referred to as extraction of ions), so that charge transfer, i.e., current flow, is performed. A plasma can be generated by means of an ion source and the ions extracted therefrom can be bunched into an ion beam (i.e. a directed current composed of ions) and accelerated (also called ion emission).

According to various embodiments, the reason identified as a parasitic coating of the ion source is: the ions extracted from the plasma also partially collide with an electrode operating as a cathode (hereinafter simply referred to as cathode), thereby stripping the electrode (e.g., atomization, i.e., sputtering), and the released material is transferred onto the anode here. The reason is further identified as: material stripped from the substrate (e.g., sputtered material) may be transferred to the anode. Furthermore, it can be appreciated that: the greater the kinetic energy of each ion, the greater the amount of material transferred from the substrate to the anode.

As the amount of material on the anode increases, the risk increases that the layer formed in the process detaches from the anode and contacts the cathode. If a short circuit is thus formed, ion irradiation is interrupted and ventilation of the facility may be required so that the ion source can be cleaned. In the case of certain substrates, the material deposited at the anode may also be electrically insulating, which gradually inhibits the electrical effectiveness of the anode (i.e., passivates it) until the process would also need to be interrupted to clean the ion source.

According to various embodiments, the ion source may be used to irradiate the substrate with ions (also referred to as ion irradiation). Ion irradiation can atomize (also known as sputtering) and/or remove foreign matter (such as water, adsorbates, or oxides) from the substrate by interacting with the irradiated surface of the substrate (also known as a process item). The substrate may be irradiated, for example, for pretreatment of the substrate, for surface cleaning and/or for improving adhesion. After ion irradiation, the substrate may optionally be coated, for example without breaking the vacuum (e.g., in the same vacuum coating facility).

According to various embodiments, the ion source provided herein may be of the closed electron drift ion source (ALS) type (i.e., providing a closed trajectory on its own). ALS can produce ions with kinetic energies of hundreds to thousands of electron volts (i.e., 0.1keV to 10keV) per ion. ALS can also be used as an ion source for physical etching processes since the ion energy is in the keV range. The thickness of the layer located on the substrate can be reduced over a large area by sputtering with the aid of ions generated by an ion source.

ALS is also used for layer deposition in vacuum. In so-called Ion Beam Sputtering (in english: Ion Beam Sputtering-IBS), a so-called target material is atomized by means of ions provided by ALS. The atomized target material is then deposited on the substrate to be coated. If stringent requirements are made on the purity of the residual gas, this type of coating by physical vapor deposition by means of ALS is used, for example.

Furthermore, ALS is used for depositing diamond-like carbon layers, so-called DLC layers (DLC stands for "diamond-like carbon"), by using precursors of the forming layer such as butane.

In addition to the coating source, ALS is also used in the course of Ion-Assisted layer Deposition (in the English language: "Ion Beam Assisted Deposition" -IBAD) in order to modify the density, crystal structure, doping and/or texture of the layer deposited by means of the coating source, for example by additional Ion bombardment.

The ion source according to various embodiments makes it possible to: the use possibilities are extended, for example, to low-energy substrate irradiations, for example for substrate pretreatment. For example, although the acceleration voltage is large (e.g., in the keV range), the kinetic energy per ion impinging on the substrate (also referred to as ion energy) can be reduced to less than 100eV (electron volts) by the ion source in low ion energy operation, for example. For example, the ion source may be used as an alternative to a plasma glow process, and may also be used for mild surface activation of the substrate in a vacuum. Due to the lower ion energy, for example, the substrate surface can be prevented from being contaminated or damaged by the working gas material, the anode material and/or the cathode material by implantation. Such implantation is generally unacceptable for many applications, for example in energy sensitive substrate films or in electronic devices.

If the ion source is not operating in the low ion energy mode of operation, the extracted ions have energies greater than 1keV (also referred to as the keV range) when impinging on the substrate.

One or more additional electrodes (e.g., including electrodes subsequently referred to as third electrodes and/or subsequently referred to as fourth electrodes) enable one or more of the following:

cleaning the main electrode in an alternating voltage mode of operation, whereby the durability of the ion source can be significantly improved;

an alternating voltage operating mode, in which a plasma can additionally be generated between two further electrodes in the ion source operating mode, additional electrons being extracted from the ion source by the plasma due to the electric field gradient between the further electrodes, which additional electrons can be used to neutralize the surface charge, whereby an additional external electron source is no longer required for achieving this neutralization;

an alternating voltage mode of operation, in which ions can additionally be extracted from the ion source in a cleaning operation, since a plasma can be generated between two additional electrodes, which can be accelerated from the source onto the substrate due to the electric field gradient between the additional electrodes, which counteracts the reduction in the total ion emission due to the cleaning mode of operation;

a low ion energy mode of operation by means of a direct voltage mode of operation, whereby the field of use of the ion source can be extended to pre-treating the substrate with low energy ions in vacuum without damaging the substrate and causing contamination;

a smaller number of generators and/or switches and/or ion sources are required compared to other conventional designs that suppress parasitic coatings.

Examples of substrates, according to various embodiments, include: films, plates (e.g., made of metal, plastic, glass, silicon), tapes, meshes, granules, and the like.

Electrical floating can be understood as: separate from the reference voltage (e.g., electrical ground) and the power supply dc. Thus, the potential of a component operating in an electrically floating manner need not necessarily correspond to a reference voltage or a voltage provided by a power supply, but may assume values in between and/or be operationally dependent. For example, a component operating in an electrically floating manner may be substantially only capacitively coupled with surrounding components. The potential of the electrically floating-mode-operated component can then be derived, for example, as a result of capacitively coupled-in voltages.

Fig. 1 shows a schematic side or cross-sectional view (viewed transverse to direction 105) of an ion source 100 according to various embodiments. The ion source 100 may include one or more electrodes 102a, 102b, 102c and form one or more magnets 104 of a magnetic field source 104.

The plurality of electrodes 102a, 102b, 102c may be mounted (e.g., held) in pairs, electrically insulated (dc isolated) from each other. Electrical separation is understood to mean that the electrical resistance between two electrodes is greater than about 10³Ohm (Ω), e.g., greater than about 10⁴Ω, e.g. greater than about 10⁵Ω, e.g. greater than about 10⁶Omega. Electrical separation is to be understood as meaning that the electrical conductivity between the two electrodes is less than 10 of the electrical conductivity of each of the two electrodes^-3(e.g., less than 10)^-6Or 10^-9)。

For example, the electrodes may be spatially separated from each other in pairs, e.g. by means of a gap therebetween and/or by means of an electrically insulating (e.g. dielectric) material therebetween. To this end, the ion source 100 may include, for example, one or more holding devices (not shown) that provide a gap and/or have an electrically insulating material.

A dielectric material is understood to mean a material (for example a solid) in which the existing charge carriers are localized (i.e. not freely movable). The dielectric material may be electrically insulating.

The plurality of electrodes 102a, 102b, 102c includes: a first electrode 102a, a second electrode 102b (also referred to as a main electrode), and a third electrode 102c (illustratively an additional electrode). The first electrode 102a, the second electrode 102b, and/or the third electrode 102c may be, for example, electrically conductive. The first electrode 102a and/or the third electrode 102c may, for example, comprise a greater magnetic permeability than the second electrode 102 b. The first electrode 102a and/or the third electrode 102c may for example be magnetizable (e.g. ferromagnetic, e.g. soft magnetic) or may at least comprise a magnetizable (e.g. ferromagnetic, e.g. soft magnetic) material, i.e. for example an iron-containing material. The second electrode 102b may be, for example, non-magnetic, or may comprise at least one non-magnetic material.

As an exemplary application, the second electrode 102b operating as an anode may be non-magnetic, and the first electrode 102a and/or the third electrode 102c operating as an electrode may be magnetic, in order to concentrate the magnetic flux density from the magnet into the gap.

The first electrode 102a includes a recess 106. The first electrode 102a may be, for example, trough-shaped or include at least one housing. The recess 106 may, for example, extend from the direction 105 (also referred to as emission direction 105) into the body of the first electrode 102.

The channel-shaped first electrode 102a may, for example, comprise a bottom wall defining a recess 106 opposite to the direction 105. The channel-shaped first electrode 102a may also comprise, for example, a circumferential side wall which defines a recess 106 in the planes 103, 101 (which are transverse to the direction 105).

The second electrode 102b may be disposed in the recess.

The third electrode 102c may at least partially cover the recess 106 and be penetrated by a gap 108, which (at least partially) exposes the second electrode 102 b. The third electrode 102c can be designed, for example, in the shape of a cap with respect to the slot shape of the first electrode 102 a.

The gap 108 may, for example, pass through the third electrode 102c along the direction 105 and/or along a direction away from the second electrode 102 b.

The magnetic field source 104 may be designed and arranged such that it provides a magnetic field 110 in the gap. The magnetic field source 104, e.g., one or more magnets thereof, may be disposed, e.g., separately (spatially and/or electrically) from the third electrode 102c, or may be at least partially (i.e., partially or fully) integrated into the third electrode. The magnetic field source 104 may be designed such that a magnetic field 110 is generated and coupled on mutually opposite sides of the gap 108.

The magnetic field source 104 may, for example, comprise two opposite magnetic poles, also referred to as north (N) and south (S) for simplicity. The gap 108 may be disposed between the north pole (N) and the south pole (S).

In an example, the field strength of the magnetic field 110 in the gap 108 may be in a range of about 1 kilo-ampere per meter (kA/m) to about 1000kA/m, such as in a range of about 10kA/m to about 100 kA/m. Of course, field strengths with higher or lower values may also be provided, for example by means of modifying the electrode geometry and/or the magnetization of the magnet.

In one example, the expansion of the gap may be less than 6mm, for example in the range of about 2mm to about 6mm, for example in the range of about 4mm to about 6mm or in the range of about 2mm to about 4 mm.

Other embodiments of the ion source 100 are described below.

Fig. 2 shows a schematic side or cross-sectional view (viewed transverse to direction 105) of the ion source 100 according to various embodiments 200, wherein the ion source 100 further comprises a plurality of dielectric holding structures, wherein a first dielectric holding structure 202a holds the second electrode 102b and electrically separates it from the first electrode 102a (e.g., dc separation), and a second dielectric holding structure 202b holds the third electrode 102c and electrically separates it from the first electrode 102a (e.g., dc separation). Each retaining structure 202a, 202b may, for example, comprise or be formed from a dielectric material (also referred to as a dielectric). The second electrode 102b and/or the third electrode 102c may be supported at the first electrode 102a or supported there, for example by means of respective holding structures 202a, 202b, but this is not essential.

Fig. 3 shows (from direction 105) a schematic side or cross-sectional view of an ion source 100 according to various embodiments 300, which may optionally be designed according to embodiment 200. According to the embodiment 300, the third electrode 102c comprises a plurality of (e.g. plate-shaped) sections 302, 304, which are spatially separated from each other by means of the gap 108. In other words, the gap 108 is formed between the segments 302, 304.

For example, the gap 108 may extend along a closed path (also referred to as a gap path). The path may for example extend in a plane 103a, 101, which is preferably substantially transverse to the direction 105.

The gap path can generally comprise one or more sections extending in a curved manner and/or one or more sections extending in a straight manner. For example, as shown in the figures, the gap path can comprise two sections running linearly and parallel to one another, which are connected to one another at the end sides (also referred to as reversal regions) by means of in each case curved running sections. The gap path may of course also be polygonal. Each curved stretch section minimizes electron losses and electric field peaks as compared to the angular section. Of course, in general, the gap path may also include rounded corners, which also minimizes electron losses and electric field peaks. For example, the gap path may also be elliptical, for example circular (in which case the ion source is also referred to as a circular source).

The segments 302, 304 may, for example, comprise a (e.g. frame-shaped) first segment 302 having a through hole and a second segment 304 arranged in the through hole. Alternatively or additionally, the segments 302, 304 may for example comprise a (consecutive) first segment 302 and a second segment 304, wherein the first segment 302 surrounds the second segment 304.

One or more of the plurality of (e.g., plate-shaped) segments 302, 304 may, for example, comprise or be formed from a ferromagnetic (e.g., soft magnetic) material, such as a metal. Alternatively or additionally, one or more of the plurality of (e.g., plate-shaped) segments 302, 304 may include or be formed from an electrically conductive material, such as a metal.

The plurality of segments 302, 304 may be magnetically coupled to each other, for example, by means of a magnetic field source 104. For example, the magnetic field source 104 may generate a magnetic field that is directed through each of the plurality of segments 302, 304 and extends across the gap 108 between the plurality of segments 302, 304.

Fig. 4 shows a schematic side view or cross-sectional view (viewed transversely to direction 105) of an ion source 100 according to various embodiments 400, which may optionally be designed according to embodiments 200 or 300.

According to embodiment 400, the third electrode 102c includes a first section 302 having two sections and a second section 304 disposed between the two sections. For example, two sections of the third electrode 102c may be consecutive.

Alternatively or additionally, the second electrode 102b according to embodiment 400 has a plurality of sections 402, 404, between which gaps are formed. The two sections 402, 404 of the second electrode 102b may be consecutive, for example. For example, each of the two sections 402, 404 of the second electrode 102b may be exposed (e.g., partially or fully exposed) by the gap 108 of the third electrode 102 c.

Fig. 5 shows a schematic side view or cross-sectional view (viewed transversely to direction 105) of an ion source 100 according to various embodiments 500, which may optionally be designed according to one of the embodiments 200 to 400. According to embodiment 500, one or more magnets of the magnetic field source 104 are disposed in the recess 106, for example, between two sections of the second electrode 102 b.

The magnetic field source 104 may, for example, be designed (e.g., arranged and/or oriented) such that the in particular generated magnetic field 110 is coupled into the third electrode 102c (e.g., the second section 304 thereof) and/or the first electrode 102 c. For example, the magnetic field source 104 may generate a magnetic field that is directed through the first electrode 102a and the third electrode 102c, and through the gap 118 between the two electrodes 102a, 102 c.

Fig. 6 shows a schematic side view or cross-sectional view (viewed transversely to direction 105) of an ion source 100 according to various embodiments 600, which may optionally be designed according to one of the embodiments 200 to 500. According to embodiment 600, the gap 108 (also referred to as first gap 108) is delimited on mutually opposite sides by the faces 302o, 304o (also referred to as limiting faces or wall faces) of the third electrode 102 running obliquely to one another, which gap passes through the third electrode 102 c. This optimizes the ion beam shaping and minimizes parasitic fogging effects at the third electrode 102 or the first and second sections 302, 304 thereof.

Fig. 7 shows a schematic side view or cross-sectional view (viewed transversely to direction 105) of an ion source 100 according to various embodiments 700, which may optionally be designed according to one of the embodiments 200 to 600. According to embodiment 700, the plurality of electrodes has a fourth electrode 102d (at the additional electrode). The fourth electrode 102d can be designed substantially like the third electrode 102c and/or be held by means of a corresponding third holding structure 202 c. The fourth electrode 102d may be, for example, electrically (e.g., dc separated) and/or spatially separated from the third electrode 102 c.

The fourth electrode 102d may for example be magnetizable (e.g. ferromagnetic, e.g. soft magnetic) or may at least comprise a magnetizable (e.g. ferromagnetic, e.g. soft magnetic) material, i.e. for example an iron-containing material. The fourth electrode 102d may, for example, have a greater magnetic permeability than the third electrode 102 c.

Of course, the fourth electrode 102d may also be non-magnetic or at least comprise a non-magnetic material. The fourth electrode 102d may, for example, have the same magnetic permeability as the second electrode 102 b. The first electrode 102a and/or the third electrode 102c may, for example, have a greater magnetic permeability than the fourth electrode 102 d. This achieves that: a plasma is generated in the gap 108 of the third electrode 102c thereunder and a correspondingly more localized plasma generation is achieved. In this case, the magnetic field strength in the gap 108 of the third electrode 102c may be greater than the magnetic field strength in the gap 108 of the fourth electrode 102d (the magnetic field in the gap of the fourth electrode may, for example, substantially disappear or may be only a small stray field).

The third electrode 102c may be disposed between the second electrode 102b and the fourth electrode 102 d. The additional gap 108 (also referred to as the second gap 108) may be oriented through the fourth electrode 102d toward the second electrode 102 and/or oriented toward the first gap 108 (e.g., extending along a linear path, such as extending along direction 105).

The second gap 108 through the fourth electrode 102d may be defined, for example, on mutually opposite sides by faces (also referred to as limiting faces) of the fourth electrode 102d running obliquely to one another. Alternatively, the limiting surfaces of the fourth electrode 102d may have a greater spacing from each other than the limiting surfaces of the third electrode 102 c. This minimizes the effect of parasitic fogging at the boundary surface of the fourth electrode 102 d.

Other embodiments of the ion source 700 and modes of operation thereof are described below. For simplicity of understanding, shorter reference numerals are used.

Fig. 8 shows a schematic side view or cross-sectional view (viewed transversely to direction 105) of an ion source 100 according to various embodiments 800, which may optionally be designed according to one of the embodiments 200 to 700. In the following, the fourth electrode 102d (also referred to as electrode 1) is provided with reference numeral (1), the second electrode 102b with reference numeral (2), the optional water cooling of the second electrode 102b and/or the first electrode 102a with reference numeral (3), the dielectric of the first holding structure 202a with reference numeral (4), the first electrode 102a (also referred to as body) with reference numeral (5), the gap 108 (also referred to as ion extraction gap) with reference numeral (6), the permanent magnet of the magnetic field source 104 with reference numeral (7), the magnetization direction of the magnetic field 110 with reference numeral (8), the optional gas inlet is provided with reference numeral (9), the dielectric of the second holding structure 202b is provided with reference numeral (10), the optional wear body (also referred to as a liner) of the second electrode 102b is provided with reference numeral (11), and the third electrode 102 (also referred to as an additional electrode or electrode 12) is provided with reference numeral (12).

The first mode of operation (also referred to as an ac voltage mode of operation) of the ion source 100 may include: the first electrode 102a and the fourth electrode 102d are provided with the same potential 802 (e.g., reference potential 802), for example, by the first electrode and the fourth electrode being placed at the same (e.g., time-invariant) voltage (e.g., reference voltage). The reference potential may be, for example, electrical ground. In other words, the voltage difference between the first electrode 102a and the fourth electrode 102d may be substantially zero. The fourth electrode 102d can also be operated in an electrically floating manner independently of the first electrode 102 a. If the fourth electrode 102d is not present, the reference voltage 802 may be applied only at the first electrode 102 a.

For example, the voltage or potential values described herein may be based on a reference potential even if the reference potential is different from electrical ground. In other words, the reference voltage may have a zero value. The voltages described herein may correspond to respective potentials that differ from a reference potential by the value of the voltage, and vice versa.

The first mode of operation may further include: a time-variable voltage difference 804 is provided between the second electrode 102b and the third electrode 102 c. The time-variable voltage difference 804 may be, for example, a mixed voltage or an alternating voltage.

The time-variable voltage difference 804 may generally have a greater time-variability than the voltage applied at the first electrode 102a and/or the fourth electrode 102 d. For example, the voltage applied at the first electrode 102a and/or the fourth electrode 102d may have a rate of change (voltage change per time) that is less than the time-varying voltage difference 804, e.g., a rate of change of zero.

A mixed voltage is understood to be a superposition of an ac voltage and a dc voltage. If the DC voltage of the mixed voltage is zero, an AC voltage is obtained. Thus, the mixed voltage may comprise a direct voltage not equal to zero.

The first mode of operation may also optionally include: gas is supplied to the recess 106, for example by means of a gas inlet (9). The gas may flow through the gap 108 and/or the additional gap 108, for example. Ionization of the gas may take place in the gap 108 and/or the additional gap 108, so that a plasma is formed there. Ions of the plasma may be emitted in direction 105.

The frequency of the time-varying voltage difference 804 (also referred to as an alternating frequency) may, for example, be in the range from about 0.1 hertz (Hz) to about 1000kHz, such as in the range from about 0.5 kilohertz (kHz) up to 50 kHz. The magnitude of the time-varying voltage difference 804 may be, for example, in the range of about 1 kilovolt kV (kV) to about 5kV, such as in the range of about 2kV to about 3 kV. The arithmetic time average of the time-varying voltage difference 804 (e.g., measured over a plurality of variations, such as cycles) may be, for example, zero (e.g., if the voltage is an ac voltage).

The first mode of operation enables: the second electrode 102b is periodically cleaned, as will be described in more detail below.

In one example, the ion source comprises one or more additional electrodes (12), (1), e.g. third and/or fourth electrodes (1), mounted, e.g. electrically insulated. The or each additional electrode (12) can, for example, assume the function of a conventional accelerating electrode (1). The third electrode (12) is made of a ferromagnetic (e.g. soft magnetic) electrically conductive material, preferably steel or graphite. The fourth electrode (1) is held at ground potential like the first electrode (5) and is made of a conductive material. The fourth electrode (1) may optionally be electrically floating. The fourth electrode (1) is preferably not ferromagnetic. The shape of the fourth electrode (1) follows the inclined opening of the gap (6) of the third electrode, also called ion extraction slit. The first electrode (5) is preferably made of a ferromagnetic (e.g. soft magnetic) material, for example steel. The electrodes (1), (2) and (12) are kept electrically insulated from each other by means of a dielectric (10).

Fig. 9 shows a schematic side view or cross-sectional view (viewed transversely to direction 105) of an ion source 100 according to various embodiments 900, which may optionally be designed according to one of the embodiments 200 to 800.

The second mode of operation (also referred to as a dc voltage mode of operation) of the ion source 100 may include: the first electrode 102a and the second electrode 102b are provided with the same potential 802 (e.g., reference potential 802), for example, by applying the same (e.g., time-invariant) voltage (e.g., reference voltage) at the first electrode and the second electrode. The reference potential may be, for example, electrical ground. In other words, the voltage difference between the first electrode 102a and the second electrode 102c may be substantially zero.

The second mode of operation may further include: a time-invariant voltage difference 806 is provided between the first electrode 102a and the third electrode 102 c. The time-invariant voltage difference 806 may be, for example, a dc voltage.

The time-invariant voltage difference 806 may have substantially the same time-variability as applied at the first electrode 102a and/or the second electrode 102 b. For example, the voltage or time-invariant voltage difference 806 applied at the first electrode 102a and/or the second electrode 102b may have a rate of change of zero.

The fourth electrode 102d, if present, may be dc separated, e.g., completely dc separated (also referred to as electrically floating), from the first electrode 102a and/or the third electrode 102 c. This achieves that: the fourth electrode 102d exerts a better shielding effect with respect to the third electrode 102c and allows for an optimized ion beam shaping. Thus, the fourth electrode 102d may exchange charge only via free carriers outside the gap 108, such that the potential of the fourth electrode is coupled with the potential of the plasma outside the gap 108.

The second mode of operation may also optionally include: gas is delivered to the recess 106. Gas may flow through the gap 108 and/or the additional gap 108, for example. Ionization of the gas may occur in the gap 108 and/or the additional gap 108 such that a plasma is formed. Ions of the plasma may be emitted in direction 105.

The direct voltage operation realizes that: low energy ions are extracted at the substrate (also referred to as a low ion energy mode of operation), which will be described in more detail below.

Fig. 10 shows a schematic side view or cross-sectional view (viewed transversely to direction 105) of an ion source 100 according to various embodiments 1000, which may optionally be designed according to one of the embodiments 200 to 900. According to embodiment 1000, the third electrode 102c and the fourth electrode 102d are substantially identical in terms of the spacing (also referred to as a bounding spacing) of their bounding surfaces (also referred to as a shielding configuration) from each other. The shielding configuration achieves: the fourth electrode 102d and the third electrode 102c substantially completely overlap such that shielding of the third electrode 102c is maximized and the potential and effectiveness of the fourth electrode 102 is better incorporated into the overall configuration.

Alternatively, the third electrode 102c and the fourth electrode 102d may differ from each other in the angle 1002 (also referred to as a limit angle) by which the limit interfaces extend toward each other. For example, the third electrode 102c may have a smaller clearance angle 1002 than the fourth electrode 102 d. For example, the third electrode 102c may have a substantially zero clearance angle. For example, the fourth electrode 102d may have a confinement angle of about 60 ° to about 120 °, such as a confinement angle of about 90 °.

For example, the additional electrode (12) can have a constant limiting distance of the emission gap (6). The limiting distance of the fourth electrode 102d (also referred to as shielding electrode) can be matched thereto.

This enables, for example, improved ion extraction in the alternating voltage mode of operation. Obviously, the ion source 100 according to embodiment 1000 may also be operated in a direct current mode of operation.

In the shielding configuration, the emission gap (6) through the third electrode (12) can be formed, for example, without tilting, over the entire thickness of the third electrode (12). The limiting spacing 1004 (also referred to as gap width) may then be constant over the entire thickness of the third electrode (12). At the same time, for example, in the case of sidewalls 302o, 304o bounding the extraction opening (6) which maintain the inclination of the fourth electrode (1), the gap width 1004 of the emission gap (6) of the fourth electrode (1) can be matched at its foot point to the gap width 1004 of the third electrode (12) lying therebelow.

Fig. 11 shows a schematic side view or cross-sectional view (viewed transversely to direction 105) of an ion source 100 according to various embodiments 1100, which may optionally be designed according to one of the embodiments 200 to 1000. According to embodiment 1100, ion source 100 has fourth electrode 102d and also has dark field shield 1102. In principle, again, a direct voltage operating mode and an alternating voltage operating mode may be selected.

The dark field shield 1102 may, for example, include one or more wall elements that physically contact and/or electrically couple the first electrode 102a and/or the fourth electrode 102d to each other.

The dark field shield 1102 may be disposed, for example, electrically and/or spatially separated from the third electrode 102 c.

The dark field shield 1102 may for example comprise two wall elements between which four of the plurality of electrodes 102a, 102b, 102c, 102d are arranged. In this manner, the dark field shield suppresses the formation of parasitic plasma at the end face of the third electrode 102c outside the ion source.

The third electrode (12) may, for example, be integrated into the ion source 100 such that no parasitic plasma discharge occurs outside or inside the ion source 100. The dark field spacing required for this purpose between components directly adjacent to one another at different potentials in the interior of the ion source 100 is in the range from about 0.5 millimeters (mm) to about 2mm or about 3 mm. In the outer space of the ion source 100, the additional electrode (12) can be covered, for example, by a dark field shield (14), preferably by a dark field shield composed of an electrically conductive material.

Instead of or in addition to a separate dark field shield, the dark field shield may also be an integral part of the first electrode 102 a.

Fig. 12 shows a schematic flow diagram of a method 1200 for operating the ion source 100 according to various embodiments, which may optionally be designed according to one of the embodiments 200 to 1100. The method 1200 may illustratively operate the ion source 100 according to an alternating voltage mode of operation. The method 1200 may be implemented, for example, by means of a control device.

The method 1200 includes: in 1201, a first voltage is applied to the second electrode 102b and/or the third electrode 102 c; at 1203, a second voltage (e.g., electrical ground) is applied at the first electrode 102a and optionally at the fourth electrode 102d (if present); and optionally in 1205, delivering a gas such that the gas flows through the gap; and optionally in 1207, the substrate is irradiated by means of the ion source 100 (e.g., by means of ions emitted by the ion source).

The first voltage and the second voltage may be different from each other, for example in terms of their time dependency, and/or have a spacing from each other. For example, the polarity of the first voltage relative to the polarity of the second voltage may be switched (e.g., in a regularly repeating manner). For example, the first voltage may be a mixed voltage or an alternating voltage. For example, the second voltage may be a direct current voltage or a reference voltage.

In an exemplary alternating voltage mode of operation (see, e.g., fig. 8), an alternating voltage is applied between the second electrode 102b and the third electrode 102c, and an electrical ground is applied at the first electrode 102a and, if present, the fourth electrode 102 d.

Fig. 13 shows a schematic flow diagram of a method 1300 for operating the ion source 100 according to various embodiments, which may optionally be designed according to one of the embodiments 200 to 1100. The method 1300 may illustratively operate the ion source 100 according to a dc voltage mode of operation. The method 1300 may be implemented, for example, by means of a control device.

The method 1300 includes: in 1301, a first voltage is applied at the third electrode 102 c; in 1303, a second voltage (e.g., electrical ground) is applied at the second electrode and/or the first electrode; and optionally in 1305, delivering a gas such that the gas flows through the gap; and optionally in 1307 the substrate is irradiated by means of an ion source 100 (e.g., by means of ions emitted by the ion source).

The first voltage and the second voltage may be different from each other, e.g. with a spacing from each other. For example, the polarity of the first voltage relative to the second voltage may be constant over time, such as during the formation of a plasma. Alternatively or additionally, the difference between the first voltage and the second voltage may be constant over time. For example, the first voltage may be a direct current voltage. For example, the second voltage may be a further direct voltage or a reference voltage.

The fourth electrode (if present) may be dc separated from the first voltage and the second voltage.

Fig. 14 shows a schematic flow diagram of a method 1400 for operating an ion source 100 according to various embodiments, which may optionally be designed according to one of the embodiments 200 to 1100. Method 1400 may include method 1200 or 1300 in 1401. The method 1400 may be implemented, for example, by means of a control device.

The method 1400 may further include: at 1403, a parameter, such as a parameter of an ion beam generated by means of an ion source, is detected; and in 1405, instructions are provided for varying a voltage applied at the ion source 100 (e.g., the third electrode and/or the fourth electrode thereof) based on the parameter.

The parameter may for example represent a state of the ion source itself (hence also referred to as an internal parameter) or a state external to the ion source (hence also referred to as an external parameter).

The internal parameter may for example represent a variable of the transport ion source. For example, for internal parameters, include: electrical power (i.e., the product of discharge voltage and discharge current), discharge current, discharge voltage, and/or the state of the gas delivered to the ion source (e.g., its pressure (also referred to as process pressure), flow rate, and/or chemical composition).

The external parameter may for example represent the state of a gas to which the ion source and/or the substrate is exposed, for example its pressure (also referred to as process pressure), flow rate and/or chemical composition.

Alternatively or additionally, the external parameter may be indicative of a state of the ion beam. For example, for parameters including: the amount of ions per unit time emitted by means of the ion beam (also referred to as the emission rate), the average energy per ion emitted by means of the ion beam (also referred to as the emission energy), the total power emitted by means of the ion beam (also referred to as the emission power), the beam divergence of the ion beam, the ion density of the ion beam. This enables closed loop control of the ion beam to be implemented.

Alternatively or additionally, the external parameter may represent a state of the substrate irradiated by means of the ion beam 100. For example, for parameters including: temperature of the substrate, voltage of the substrate, properties (e.g. chemical and/or physical) of the substrate influenced by the irradiation, changes of the substrate caused by the irradiation. This enables the implementation of closed loop control of the substrate processing.

In one example, the ion source operates in a time-constant amplified voltage, and the discharge power of the ion source is regulated and/or closed-loop controlled via the gas flux delivered to the ion source (e.g., the amount of gas per unit time).

In one example, power variations and/or current variations may also be used as controlled variables (also referred to as reference variables) instead of or in addition to voltage variations.

Fig. 15 shows a schematic flow diagram of a method 1500 for operating an ion source 100 according to various embodiments, which may optionally be designed according to one of the embodiments 200 to 1100. In 1501, method 1500 may include one of methods 1200 to 1400. The method 1500 may be implemented, for example, by means of a control device.

The method 1500 may further include: in 1503, instructions are provided for applying a second voltage at the substrate processed by means of the ion source; and optionally, at 1505, instructions are provided for varying the second voltage based on the parameter.

Fig. 16 shows a schematic control diagram of an operating device 1600 according to various embodiments. The manipulation apparatus 1600 may comprise a control device 1602. The control device 1602 may be designed to implement one of the methods 1200 to 1500. To this end, the control device 11602 may comprise a processor designed to implement one of the methods 1200 to 1500. For example, the processor may be designed to output corresponding instructions.

Alternatively or additionally, the processor may be designed to: receiving and processing corresponding instructions. For example, the instructions may be implemented by means of code segments. For example, the code segment may comprise instructions that, when executed by a processor, cause the processor to perform one of the methods 1200 to 1500.

The term "control device" may be understood as an entity implementing any type of logic, e.g., having an interconnect and/or a processor, where the entity may execute software, e.g., stored in a storage medium, firmware, or a combination thereof, and may output instructions based thereon. The control device may be configured, for example, by means of code segments (e.g. software). The control device may have or be formed by a programmable logic control device (SPS), for example.

If the method is implemented by means of the control device described herein, it is understood that: the control device is designed to provide (and for example output) corresponding instructions to carry out one or more parts of the method, for example to apply a voltage.

According to various embodiments, the data storage (also referred to more generally as storage media) may be a non-volatile data storage. The data memory may, for example, have or be formed by a hard disk and/or at least one semiconductor memory (e.g. read-only memory, random access memory and/or flash memory). The read-only memory may be, for example, an erasable programmable read-only memory (also referred to as an EPROM). The random access memory may be a non-volatile random access memory (also referred to as NVRAM- "non-volatile random access memory"). For example, one or more of the following may be stored in the data store: a code segment representing a method, one or more parameters of a method.

The term "processor" may be understood as any type of entity allowing to process data or signals. For example, data or signals may be processed in accordance with at least one (i.e., one or more) specific function performed by a processor. The processor may have or be formed from analog circuitry, digital circuitry, mixed signal circuitry, logic circuitry, a microprocessor, a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), a Digital Signal Processor (DSP), a programmable gate array (FPGA), integrated circuitry, or any combination thereof. Any other type of implementation of the respective functions described in more detail below may also be understood as a processor or logic circuit, for example, a virtual processor (or virtual machine) or more than one decentralized processor (for example, a computational load distribution between processors) connected to one another, for example, by means of a network, distributed arbitrarily in space, and/or having any share of the implementation of the respective functions. The same generally applies to logic implemented in other ways to implement the corresponding functions. It is to be understood that: one or more of the method steps described in detail herein may be performed (e.g., carried out) by a processor via one or more specific functions performed by the processor.

The instructions 1601 output by the control device 1602 may be supplied, for example, to a voltage source 1604 (if present) of the control device 1600. The voltage source 1604 may be designed to generate and output one or more voltages 1603 (e.g., a first voltage and/or a second voltage) according to the instructions 1601.

Fig. 17 shows a processing apparatus 1700 according to various embodiments, wherein the processing apparatus 1700 has a manipulation apparatus 1600 and an ion source 100.

The voltage source 1604 may be designed to: one or more voltages 1603 (e.g., a first voltage and/or a second voltage) are generated and delivered to the ion source 100, for example, applied at one or more electrodes of the ion source 100. For example, the voltage source 1604 may be designed to: the voltage 1603 applied at the second electrode 102b and/or the voltage 1603 applied at the third electrode 102c is provided and/or changed. For example, the voltage source 1604 may be designed to: the voltage 1603 applied at the second electrode 102b and/or the third electrode 102c is changed according to an instruction 1601 output by the control device 1602.

For example, the voltage source 1604 may be designed to provide a voltage 1603 applied at the fourth electrode 102 d. For example, the voltage source 1604 may be designed to: the voltage 1603 applied at the fourth electrode is changed according to an instruction 1601 output by the control device 1602.

In other words, the voltage 1603 may be used as a manipulated variable 1603 by which the ion beam 100s may be controlled and/or closed-loop controlled. Of course, it is to be understood that: alternatively or in addition to the voltage 1603, the current delivered to the ion source or corresponding electrode may be used as the manipulated variable 1603. More generally, examples of manipulated variables may include: electrical power (i.e., the product of discharge voltage and discharge current), discharge current, discharge voltage, and/or the state of the gas delivered to the ion source (e.g., its pressure, flow rate, and/or chemical composition).

The ion source 100 may provide the ion beam 100s as a function of one or more manipulated variables 1603 delivered to the ion source 100. For example, the state of the ion beam 100s may be a function of one or more manipulated variables 1603, such as voltages applied at the third electrode 102c and/or the fourth electrode 102 d.

In one example, the ion beam 100s is provided at a constant voltage as a function of discharge current (or ion current) or discharge power.

For example, the current and power may be a function of manipulated variables of the process pressure and of the applied voltage.

Fig. 18 shows a schematic flow diagram of a processing device according to various embodiments 1800, wherein the processing device also has a substrate 1802 which is irradiated by means of the ion beam 100 s.

A number of exemplary embodiments of the alternating current mode of operation or the direct current mode of operation are described below.

Fig. 19 shows a number of schematic diagrams of example embodiments of an alternating current operating mode 1900 according to various embodiments, wherein a first graph 1901 is a voltage 1901 (e.g., in volts) over time t (e.g., in seconds). The voltage profile 1902 plotted in the first diagram 1901 may represent a time-varying voltage applied to or at the second electrode 102b (also referred to as electrode 2).

As can be seen, the alternating current operation 1900 may be performed according to a repeating sequence. The sequence may include two phases (also illustratively referred to as a cathode phase 154 and an anode phase 152) that differ from each other in the polarity of the time-varying voltage 1902. This achieves that: the second electrode 102b is operated alternately as a cathode (in the cathode phase 154) and as an anode (in the anode phase 152).

The second and third graphs 1903 and 1905, respectively, show a voltage 1901 along a path x (e.g., in meters) leading from the first electrode 102a to the substrate. A second plot 1903 shows the state in the anodic phase 152 and a third plot 1905 shows the state in the cathodic phase 154. The dashed lines represent the corresponding floating potentials.

In the anode phase 152, ions are emitted by the ion source 100 in the direction 105 of the substrate (also referred to as ion extraction), i.e., the plasma is a source of ions emitted away from the ion source 100 (also referred to as ion source operation). In the cathode phase 154, ions of the plasma are received 151 from the ion source 100, e.g. in a direction 115 towards the second electrode 102b, i.e. the second electrode 102b provides an ion trap (also referred to as ion trap operation or cleaning operation). The received ions bombard the second electrode 102b with ions, which cause material to be stripped from the second electrode (also referred to as cleaning the second electrode 102 b).

In the ion source mode of operation, the electrode 2 may operate as an anode and the electrode 12 may operate as a cathode. In the cleaning mode of operation, the electrode 12 may operate as an anode and the electrode 2 may operate as a cathode.

In one example, the ion source is operated by means of an alternating voltage between the second electrode (2) and the third electrode (12), for example, having an amplitude greater than 1kV (e.g. up to ± 5kV), while the fourth electrode (1) and the first electrode (5) are at ground potential. However, the fourth electrode (1) may also be operated electrically floating. The fourth electrode (1) is preferably made of an electrically conductive material.

For example, the frequency of the alternating voltage is in a range between about 0.1 hertz (Hz) to about 1000 kHz.

The alternating voltage or the alternating voltage pulses thereof can be sinusoidal, stepped, trapezoidal or rectangular, bipolar. The alternating voltage may have a symmetrical or asymmetrical value and/or pulse duration. The alternating voltage may optionally have a switch-off time between individual pulses of one cycle.

During the anode phase 152, i.e. the second electrode (2) is operated as anode and the third electrode (12) as cathode, the plasma source is operated in ion source operating mode and ions with energies in the keV range can be extracted from the gap (6), also referred to as emission opening, and delivered to the substrate to be processed.

In the cathode phase 154, i.e. during operation of the second electrode (2) as cathode and the third electrode (12) as anode, the plasma source is operated in a cleaning mode of operation and the surface of the second electrode (2) is stripped (e.g. atomized, i.e. sputtered) by bombardment of the pillars created in the plasma and thereby released from the deposit. This achieves, for example, that the second electrode remains free of parasitic coatings.

Since the surface of the second electrode (2) can be eroded during the cleaning mode of operation, the second electrode can have a wear body (11) (so-called pad) which is easily replaceable, the wear body facing the gap 108. The pads are electrically conductive, or have or are formed from an electrically conductive material, and/or may be non-magnetic (e.g., non-ferromagnetic).

Fig. 20 shows a schematic diagram of an example embodiment of a dc mode of operation 2000 showing a voltage 1901 along a path x (e.g., in meters) leading from the second electrode 102b to the substrate, according to various embodiments. Illustratively, the second electrode 102b and the substrate are at substantially the same potential such that ions that traverse the path from the second electrode 102 to the substrate are substantially braked to a velocity at or near zero. This results in a minimization of the kinetic energy per ion transferred to the substrate upon ion impact. In other words, the dc current mode of operation 2000 enables extraction of low energy ions at the substrate (also referred to as a low ion energy mode of operation).

In one example, the ion source 100 operates with a direct current voltage between the second electrode (2) and a third electrode (12), wherein the third electrode (12) has a potential that is negative (e.g., up to-5 kV) with respect to the second electrode (2) at ground potential. The first electrode (5) may be at ground potential and the fourth electrode (1) may preferably be electrically floating or connected to ground potential. Due to the gradient of the electric field strength between the second electrode (2) and the third electrode (12), ions are accelerated from the gap (6), also called the emitter gap, in the direction of the grounded or electrically floating substrate.

Thereby, there is no or only a small potential difference between the second electrode (2) and the substrate, which potential difference affects the plasma potential and thus the initial energy of the ions. The energy gain of the ions extracted from the emission gap (6) due to acceleration due to the potential difference between the plasma and the substrate is then, for example, in the eV range of at most two digits. In order to minimize the charging of the electrically floating substrate and thus the screening of the ion beam, an additional electron source may be present in addition to the ion source, which neutralizes the surface charge of the substrate or of other installations in the environment by means of the electrons supplied by the additional electron source. Since the low ion energy does not cause any or only a small amount of parasitic coating at the second electrode due to sputtering of the substrate or the third electrode (12), an additional cleaning phase (i.e. commutation of the dc voltage) is not absolutely necessary, but can be used well if desired.

Fig. 21 shows a plurality of schematic views 2101, 2103 of an exemplary embodiment of an alternating current mode of operation 1900 according to various embodiments 2100, in which the ion source 100 has a shielded configuration showing a voltage 1901 along a path x (in meters) leading from the second electrode 102b to the substrate. Again, fig. 2101 shows the anode phase 152 and fig. 2103 shows the cathode phase 154.

In addition to better beam focusing, the shielding configuration achieves: the fourth electrode (1) is incorporated into a circuit for generating plasma, for example in an alternating voltage mode of operation.

Thus, in the anode phase 152 (ion source operation mode), a plasma may additionally be generated between the fourth electrode (1) and the third electrode (12), whereby electrons may be extracted from the plasma due to the electric field gradient between the fourth electrode (1) (in case of an anode) and the third electrode (12) (in case of a cathode). The electrons can be used to neutralize the surface charge of the substrate, thereby achieving: an additional electron source is not necessarily required if the substrate is electrically floating and/or non-conductive and surface charges have to be neutralized.

In the cathode phase 152 (cleaning mode of operation), ions can also be extracted from the plasma, since an additional plasma is formed between the fourth electrode (1) and the third electrode (12), whereby ions can be accelerated from the plasma onto the substrate due to the electric field gradient between the fourth electrode (1) (in this case the cathode) and the third electrode (12) (in this case the anode). Thus, the extracted ions enable, for example, a pre-treatment or physical etching of the substrate surface, thereby enabling continuous ion source operation including cleaning of the second electrode (2).

Different examples relating to what has been described above and what is shown in the drawings are described below.

Embodiment 1 is an ion source, comprising: a plurality of electrodes mounted electrically separated from each other (e.g., dc separated) and including: a first electrode having a recess; a second electrode disposed in the recess; a third electrode partially covering the recess and through which a gap passes, the gap exposing the second electrode; one or more magnets designed to provide a magnetic field in the gap.

Example 2 is the ion source according to example 1, further comprising: a first dielectric holding structure that holds the second electrode (e.g., supported at the first electrode) and electrically separates it from the first electrode (e.g., direct current separation); and/or a second dielectric holding structure that holds and electrically separates (e.g., dc separates) the third electrode (e.g., supported at the first electrode) from the first electrode.

Example 3 is an ion source, comprising: a first electrode having a recess; a second electrode disposed in the recess; a first dielectric holding structure that holds the second electrode and electrically separates it from the first electrode (e.g., dc separation); a third electrode partially covering the recess and through which a gap passes, the gap at least partially (i.e., partially or completely) exposing the second electrode; a second dielectric holding structure that holds the third electrode and electrically separates it from the first electrode (e.g., dc separation); one or more magnets designed to provide a magnetic field in the gap.

Example 4 is the ion source according to any one of examples 1 to 3, wherein the third electrode has a first plate-shaped section and a second plate-shaped section, a gap being formed between the sections.

Example 5 is the ion source of any of examples 1-4, wherein the third electrode has or is formed of a ferromagnetic material, the ferromagnetic material preferably abutting the gap (e.g., on both sides of the gap).

Example 6 is the ion source of any of examples 1 to 5, wherein the one or more magnets are disposed outside the recess and/or abut the third electrode.

Example 7 is the ion source of any of examples 1 to 6, wherein the one or more magnets are disposed within the recess and/or adjacent to the first electrode.

Example 8 is the ion source according to any one of examples 1 to 7, wherein the first electrode is designed to be slot-shaped; and/or wherein the third electrode is designed (for example at least sectionally) plate-shaped.

Example 9 is the ion source of any of examples 1 to 8, wherein the gap has one or more sections extending longitudinally along a plane of the third electrode (e.g., two sections side-by-side to each other).

Example 10 is the ion source of any of examples 1 to 9, wherein the gap extends along a closed path. The ion source can also work if the path of the gap does not have to be closed, but is significantly less uniform in terms of ion current distribution and less efficient in terms of ion current extraction.

Example 11 is the ion source according to any one of examples 1 to 10, wherein the gap is defined on sides opposite to each other by faces of the third electrode extending obliquely to each other.

Example 12 is the ion source of any of examples 1 to 11, wherein the gap passes through the third electrode in a direction away from the second electrode.

Example 13 is the ion source (e.g., the plurality of electrodes) of any of examples 1 to 12, further comprising: a fourth electrode through which an additional gap passes (wherein, for example, the third electrode is disposed between the first electrode and the fourth electrode); wherein the gap is disposed between the additional gap and the second electrode (e.g., the gap and the additional gap continue with each other); optionally, a third dielectric holding structure that holds and electrically separates the fourth electrode from the third electrode.

Example 14 is the ion source according to example 13, wherein the additional gap passes through the fourth electrode in a direction away from the second electrode (e.g., extending through the gap).

Example 15 is the ion source according to any one of examples 13 or 14, wherein the additional gap is defined on sides opposite to each other by additional faces of the fourth electrode extending obliquely to each other.

Example 16 is the ion source according to example 13, wherein a spacing between the two additional faces substantially corresponds to a spacing between two faces of the third electrode, the faces defining a gap on opposite sides (e.g., running parallel to each other).

Example 17 is the ion source according to any one of examples 13 to 16, the fourth electrode designed and arranged such that there is a linear course from the fourth electrode to the second electrode, the linear course extending across the gap.

Example 18 is a method for operating an ion source according to any one of examples 1 to 17, the method comprising: applying a first voltage to (or providing instructions for) the second and third electrodes; and applying (or providing instructions for) a second voltage (e.g., ground) at the first electrode (and, if present, at the fourth electrode); wherein optionally the first voltage comprises an alternating voltage (e.g. its polarity alternates in a regularly repeating manner with respect to the second voltage).

Example 19 is a method for operating an ion source according to any one of examples 1 to 17, the method comprising: applying (or providing instructions for) a first voltage at the third electrode; and applying (or providing instructions for) a second voltage (e.g., ground) at the second electrode and the first electrode; wherein optionally the first voltage comprises a direct current voltage (e.g., its polarity and/or difference relative to the second voltage remains constant); wherein optionally the fourth electrode (if present) is dc separated from the first voltage and the second voltage.

Example 20 is a method for operating an ion source according to any one of examples 1 to 17 (e.g., example 13), the method comprising: detecting (or providing instructions for) a parameter representative of (e.g., a state of) an ion beam generated by means of an ion source; the method may include optionally varying (or providing instructions for) an electrical variable (e.g., voltage, electrical power, and/or current) delivered to the ion source (e.g., its first electrode and/or its third electrode and/or its fourth electrode and/or its second electrode) based on a parameter, optionally varying (e.g., its gas flux, its chemical composition, and/or its pressure) a gas (e.g., its gas flux, its chemical composition, and/or its pressure) delivered to the ion source (e.g., its gap) based on a parameter, where the electrical variable, for example, has a voltage (e.g., corresponds to) applied at the ion source (e.g., its first electrode and/or its third electrode and/or its fourth electrode and/or its second electrode). For example, in the case of a constant discharge voltage, the amount of gas delivered can be varied as a manipulated variable and the discharge power used as a reference variable.

Example 21 is a method for processing a substrate, the method comprising: the method of any one of examples 18 to 20, applying (or providing instructions for) a second voltage to a substrate being processed by means of the ion source.

Example 22 is a control apparatus designed to perform the method according to any one of examples 18 to 21.

Example 23 is a steering device, comprising: a control apparatus according to example 22, and a voltage source for providing a voltage applied at the substrate and/or at one or more electrodes of the ion source, wherein the voltage source is designed to vary the voltage according to a command; the manipulation device optionally further comprises: a gas flux regulator for providing a process gas flow, wherein the gas flux regulator is designed for changing an electrical characteristic variable (discharge voltage or discharge current, and/or discharge power and/or ion beam current) of the plasma discharge or ion beam.