阅读说明：本技术 显微操纵器装置和量测系统 (Micromanipulator arrangement and metrology system ) 是由 D·索拉比巴巴黑德利 T·尤特迪杰克 C·J·马松 B·D·道森 M·A·阿克巴斯 K·M 于 2020-03-13 设计创作，主要内容包括：一种用于去除物体的一部分的装置包括平台、量测设备、材料去除装置和致动器。量测设备包括辐射源、光学系统和检测器。材料去除装置包括细长元件和在细长元件的端部处的尖锐元件。平台支撑物体。辐射源生成辐射。光学系统将辐射指向物体的该部分。检测器接收被物体的该部分散射的辐射并且基于所接收的辐射输出数据。该数据包括物体的该部分的位置。致动器移动材料去除装置使得尖锐元件设置在物体的该部分的位置上。该装置在物体的该部分上施加力使得物体的该部分可以被移除。(An apparatus for removing a portion of an object includes a stage, a metrology device, a material removal device, and an actuator. The metrology apparatus includes a radiation source, an optical system, and a detector. The material removal device includes an elongated element and a pointed element at an end of the elongated element. The platform supports an object. The radiation source generates radiation. The optical system directs the radiation to the portion of the object. The detector receives radiation scattered by the portion of the object and outputs data based on the received radiation. The data includes a location of the portion of the object. The actuator moves the material removal device such that the sharp element is disposed at the location of the portion of the object. The device exerts a force on the portion of the object such that the portion of the object can be removed.)

1. A system for removing a portion of an object, the system comprising:

metrology apparatus, comprising:

a cantilever comprising a sharp element, wherein the cantilever is configured to deflect when the sharp element contacts the portion of the object;

a platform configured to support the object and position the object relative to the cantilever;

an illumination system configured to generate radiation and direct the radiation towards the cantilever, wherein a property of the radiation scattered by the cantilever is based on a deflection state of the cantilever;

a detector configured to receive scattered radiation and to generate a signal based on the received scattered radiation; and

a processor configured to receive the signal and determine one or more properties of the portion of the object,

wherein the metrology device is configured to use motion of the platform to introduce a force between the sharp element and the portion of the object to remove the portion of the object, and the force is selected based on a size of the portion of the object.

2. The system of claim 1, wherein the sharp element comprises tungsten, tungsten carbide, diamond, or ruby.

3. The system of claim 1, wherein the object comprises a wafer stage and the portion of the object comprises at least a portion of a burl.

4. The system of claim 1, wherein the portion of the object comprises a material comprising chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide, and the force is sufficient to remove the material.

5. The system of claim 1, wherein a minimum step size of movement of the stage is less than about 50 nm.

6. The system of claim 1, wherein a minimum step size of movement of the stage is less than about 10 nm.

7. The system of claim 1, wherein the portion of the object is less than about 100nm in size.

8. The system of claim 1, wherein the portion of the object is less than about 10nm in size.

9. The system of claim 1, wherein the metrology system is capable of performing determining the one or more properties of the portion of the object and removing the portion of the object in situ.

10. A system for removing a portion of an object, the system comprising:

a platform configured to support the object;

an illumination system configured to generate a beam of radiation and to direct the beam towards the portion of the object to ablate the portion of the object;

a metrology system configured to determine one or more properties of the portion of the object and generate input data based on the determined one or more properties, wherein the determined one or more properties include a position and an elevation of the portion of the object; and

a controller configured to perform operations comprising:

receiving the input data; and

controlling the ablation, wherein the controlling comprises positioning the portion of the object in a path of the beam and adjusting a parameter of the illumination system based on the input data, and the parameter comprises an average power of the beam.

11. The system of claim 10, wherein:

the determined one or more properties include a composition of a material of the portion of the object;

the material comprises chromium nitride, titanium nitride, diamond-like carbon, silicon or silicon carbide; and

the controller is further configured to adjust the parameter to ablate the material.

12. The system of claim 10, wherein the object comprises a wafer stage and the portion of the object comprises at least a portion of a burl.

13. The system of claim 10, wherein the beam comprises a wavelength between approximately 100 to 400 nm.

14. The system of claim 10, wherein the metrology system comprises an interferometer.

15. The system of claim 10, wherein the metrology system comprises an optical profiler.

16. The system of claim 10, wherein the system is configured to automatically remove portions of the object over an entire span of a surface of the object.

17. The system of claim 10, wherein the adjusting further comprises adjusting the parameters of the illumination system such that chemical bonds of the portion of the object are severed without completely ablating the portion of the object.

18. A method, comprising:

generating a radiation beam;

directing the beam toward a portion of an object;

ablating the portion of the object using the radiation beam;

determining one or more properties of the portion of the object using a metrology system;

generating, using the metrology system, input data based on the determined one or more properties, wherein the one or more properties include a position and an elevation of the portion of the object;

receiving the input data at a controller;

controlling the ablation, wherein the controlling comprises:

positioning the portion of the object in a path of the beam; and

adjusting a parameter of the illumination system based on the input data, wherein the parameter comprises an average power of the beam.

19. The method of claim 18, wherein the metrology system comprises an interferometer.

20. The method of claim 18, wherein the adjusting further comprises adjusting the parameters of the illumination system such that chemical bonds of the portion of the object are severed without completely ablating the portion of the object.

Technical Field

The present disclosure relates to micromanipulator devices and metrology systems, for example, micromanipulator devices for removing excess material at the microscopic scale.

Background

A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. Lithographic apparatus can be used, for example, to manufacture Integrated Circuits (ICs). In such cases, a patterning device (alternatively referred to as a mask or a reticle) may be used to generate a circuit pattern to be formed on an individual layer of the IC. The pattern can be transferred onto a target portion (e.g., comprising part of, one, or several dies) on a substrate (e.g., a silicon wafer). The transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. Typically, a single substrate will contain a network of adjacent target portions that are successively patterned. The known lithographic apparatus comprises: so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at one time; and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the "scanning" -direction) while synchronously scanning the target portion parallel or anti-parallel to this scanning direction. The pattern may also be transferred from the patterning device to the substrate by imprinting the pattern onto the substrate.

Substrate tables on which substrates are supported during lithography and metrology require flatness tolerances that are difficult to meet. A wafer (e.g., a semiconductor substrate) that is relatively thin (e.g., <1mm thick) compared to the width of its surface area (e.g., >100mm) is particularly sensitive to non-planarity of the substrate table. Burls on the order of tens of microns on the substrate table may warp the substrate sufficiently to adversely affect subsequent photolithography and metrology processes performed on the substrate. It is desirable to develop an apparatus and method that can precisely locate and remove microscopic protrusions on a planar surface that may be difficult to remove using other polishing or area planarization techniques.

Disclosure of Invention

In some embodiments, a micromanipulator apparatus comprises a stage, a metrology device, a material removal apparatus, and an actuator. The metrology apparatus includes a radiation source, an optical system, and a detector. The material removal device includes an elongated element and a pointed element at an end of the elongated element. The platform supports an object. The radiation source generates radiation. An optical system directs radiation to a portion of an object. The detector receives radiation scattered by the portion of the object and outputs data based on the received radiation. The data includes a location of the portion of the object. The actuator moves the material removal device such that the sharp element is disposed at the location of the portion of the object. The material removal device exerts a force on the portion of the object such that the portion of the object can be removed.

In some embodiments, a metrology system includes a stage, a radiation source, an optical system, a detector, a material removal device, and an actuator. The material removal device includes an elongated element and a pointed element at an end of the elongated element. The platform supports an object. The radiation source generates radiation. An optical system directs radiation to a portion of an object. A detector receives radiation scattered by the portion of the object and outputs data based on the received radiation, wherein the data includes a position of the portion of the object. The actuator moves the material removal device such that the sharp element is disposed at the location of the portion of the object. The material removal device exerts a force on the portion of the object such that the portion of the object can be removed and the metrology system measures a property of the removed portion of the object.

In some embodiments, a micromanipulator arrangement comprises a platform, a metrology device, a material dispensing device, and an actuator. The metrology apparatus includes a radiation source, an optical system, and a detector. The material dispensing device includes a dispensing end. The platform supports an object. The radiation source generates radiation. An optical system directs radiation to a target on an object. A detector receives radiation scattered by the projection and outputs data based on the received radiation. The data includes the position of the target on the object. The material dispensing device dispenses the bonding agent. The actuator moves the material dispensing device such that the dispensing end is disposed at the target location. The size of the bonding agent dispensed by the material dispensing device is less than about 50 microns and the minimum step size of movement of the material dispensing device is less than about 0.1 microns.

Further features of the present disclosure, as well as the structure and operation of various embodiments, are described in detail below with reference to the accompanying drawings. Note that this disclosure is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Other embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.

Drawings

The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present disclosure and, together with the description, further serve to explain the principles of the disclosure and to enable a person skilled in the pertinent art to make and use the embodiments described herein.

Figure 1A illustrates a schematic diagram of a reflective photolithography apparatus, according to some embodiments.

FIG. 1B shows a schematic diagram of a transmissive lithographic apparatus according to some embodiments.

Figure 2 illustrates a more detailed schematic diagram of a reflective lithographic apparatus according to some embodiments.

FIG. 3 depicts a schematic diagram of a lithography unit according to some embodiments.

FIG. 4 shows a schematic diagram of a substrate table according to some embodiments.

FIG. 5 illustrates a schematic diagram of a micromanipulator arrangement according to some embodiments.

FIG. 6 illustrates a schematic diagram of a metrology system, according to some embodiments.

Figures 7 and 8 illustrate a system for performing metrology measurements and accurate removal of material, in accordance with some embodiments.

FIG. 9 illustrates method steps for performing metrology measurements and accurate removal of material, in accordance with some embodiments.

Features of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. Further, in general, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The drawings provided throughout this disclosure should not be construed as being drawn to scale unless otherwise indicated.

Detailed Description

This specification discloses one or more embodiments that incorporate the features of this disclosure. The disclosed embodiment(s) are provided as examples. The scope of the present disclosure is not limited to the disclosed embodiment(s). The claimed features are defined by the appended claims.

The described embodiments and references in the specification to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

Spatially relative terms, such as "below," "lower," "above," "upper," and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures for convenience. In addition to the orientations depicted in the figures, spatially relative terms are intended to encompass different orientations of the device in use or operation. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

As used herein, the term "about" means a value for a given amount that can vary based on the particular technique. Based on the particular technology, the term "about" can mean a given amount of a value that varies within, for example, 10-30% of the value (e.g., ± 10%, ± 20%, or ± 30% of the value).

Embodiments of the present disclosure may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the disclosure may also be implemented as instructions stored on a machine-readable medium, which may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include Read Only Memory (ROM); random Access Memory (RAM); a magnetic disk storage medium; an optical storage medium; a flash memory device; electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Further, firmware, software, routines, and/or instructions may be described herein as performing certain actions. However, it should be understood that such descriptions are merely for convenience and that such actions in fact result from execution of firmware, software, routines, instructions, etc. by a computing device, processor, controller or other device.

However, before describing these embodiments in more detail, it is beneficial to present an example environment in which embodiments of the present disclosure may have an impact.

Example lithography System

Fig. 1A and 1B show schematic diagrams of a lithographic apparatus 100 and a lithographic apparatus 100', respectively, in which embodiments of the present disclosure may be implemented. The lithographic apparatus 100 and the lithographic apparatus 100' each include the following: an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. deep ultraviolet or extreme ultraviolet radiation); a support structure (e.g. a mask table) MT configured to support a patterning device (e.g. a mask, a reticle, or a dynamic patterning device) MA and connected to a first positioner PM configured to accurately position the patterning device MA; and a substrate table (e.g. a wafer table) WT configured to hold a substrate (e.g. a resist-coated wafer) W and connected to a second positioner PW configured to accurately position the substrate W. Lithographic apparatus 100 and 100' also have a projection system PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion (e.g., comprising one or more dies) C of the substrate W. In lithographic apparatus 100, patterning device MA and projection system PS are reflective. In the lithographic apparatus 100', the patterning device MA and the projection system PS are transmissive.

The illumination system IL may include various types of optical components, such as refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, for directing, shaping, or controlling the radiation beam B.

The support structure MT holds the patterning device MA in a manner that depends on the orientation of the patterning device MA with respect to the reference frame, the design of at least one of the lithographic apparatuses 100 and 100', and other conditions, such as for example whether or not the patterning device MA is held in a vacuum environment. The support structure MT may use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device MA. The support structure MT may be a frame or a table, for example, which may be fixed or movable as required. By using sensors, the support structure MT can ensure that the patterning device MA is at a desired position, for example with respect to the projection system PS.

The term "patterning device" MA should be broadly interpreted as referring to any device that can be used to impart a radiation beam B with a pattern in its cross-section, such as to create a pattern in a target portion C of the substrate W. The pattern imparted to the radiation beam B may correspond to a particular functional layer in a device being created in the target portion C to form an integrated circuit.

The patterning device MA may be transmissive (e.g., lithographic apparatus 100' of fig. 1B) or reflective (e.g., lithographic apparatus 100 of fig. 1A). Examples of patterning device MA include reticles, masks, programmable mirror arrays, or programmable LCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase-shift, or attenuated phase-shift, as well as various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in the radiation beam B which is reflected by a matrix of small mirrors.

The term "projection system" PS can encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors such as the use of an immersion liquid on the substrate W or the use of a vacuum. A vacuum environment may be used for EUV or electron beam radiation because other gases may absorb too much radiation or electrons. Thus, a vacuum environment may be provided for the entire beam path by means of the vacuum wall and the vacuum pump.

The lithographic apparatus 100 and/or lithographic apparatus 100' may be of a type having two (dual stage) or more substrate tables WT (and/or two or more mask tables). In such "multiple stage" machines the additional substrate tables WT may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other substrate tables WT are being used for exposure. In some cases, the additional table may not be the substrate table WT.

The lithographic apparatus may also be of a type wherein: wherein at least a portion of the substrate may be covered by a liquid having a relatively high refractive index, e.g. water, so as to fill a space between the projection system and the substrate. Immersion liquids may also be applied to other spaces in the lithographic apparatus, for example, between the mask and the projection system. Immersion techniques for increasing the numerical aperture of projection systems are well known in the art. The term "immersion" as used herein does not mean that a structure, such as a substrate, must be submerged in liquid, but rather only means that liquid is located between the projection system and the substrate during exposure.

Referring to fig. 1A and 1B, the illuminator IL receives a radiation beam from a radiation source SO. The source SO and the lithographic apparatus 100, 100' may be separate physical entities, for example when the source SO is an excimer laser. In such cases, the source SO is not considered to form part of the lithographic apparatus 100, 100' and the radiation beam B is passed from the source SO to the illuminator IL with the aid of a beam transmission system BD (in FIG. 1B) comprising, for example, suitable directing mirrors and/or a beam expander. In other cases, the source SO may be an integral part of the lithographic apparatus 100, 100', for example when the source SO is a mercury lamp. The source SO and the illuminator IL, together with the beam transmission system BD if required, may be referred to as a radiation system.

The illuminator IL may include an adjuster AD (in FIG. 1B) for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer and/or inner radial extent (commonly referred to as σ -outer and σ -inner, respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. IN addition, the illuminator IL may include various other components (shown IN FIG. 1B), such as an integrator IN and a condenser CO. The illuminator IL may be used to condition the radiation beam B, to have a desired uniformity and intensity distribution in its cross-section.

Referring to FIG. 1A, a radiation beam B is incident on the patterning device (e.g., mask) MA, which is held on the support structure (e.g., mask table) MT, and is patterned by the patterning device MA. In the lithographic apparatus 100, the radiation beam B is reflected from the patterning device (e.g., mask) MA. After reflection from the patterning device (e.g. mask) MA, the radiation beam B passes through the projection system PS, which focuses the radiation beam B onto a target portion C of the substrate W. With the aid of the second positioner PW and position sensor IF2 (e.g. an interferometric device, linear encoder or capacitive sensor), the substrate table WT can be moved accurately (e.g. so as to position different target portions C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor IF1 can be used to accurately position the patterning device (e.g. mask) MA with respect to the path of the radiation beam B. Patterning device (e.g. mask) MA and substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2.

Referring to FIG. 1B, radiation beam B is incident on the patterning device (e.g., mask MA), which is held on the support structure (e.g., mask table MT), and is patterned by the patterning device. After passing through the mask MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. The projection system has a pupil PPU conjugated to the illumination system pupil IPU. Part of the radiation emanates from the intensity distribution at the illumination system pupil IPU and passes through the mask pattern without being affected by diffraction at the mask pattern, and part of the radiation transmits an image of the intensity distribution at the illumination system pupil IPU.

The projection system PS projects an image MP' of the mask pattern MP, formed by the diffracted beam transmitted from the marker pattern MP by the radiation from the intensity distribution, onto a photoresist layer coated on the substrate W. For example, the mask pattern MP may include an array of lines and spaces. Diffraction of radiation at the array, as opposed to zero order diffraction, generates a deflected diffracted beam, the direction of which varies in a direction perpendicular to the lines. The undiffracted beam (i.e. the so-called zero-order diffracted beam) passes through the pattern without any change in the direction of propagation. The zero order diffracted beam passes through an upper lens or upper lens group of the projection system PS upstream of the pupil conjugate PPU of the projection system PS to the pupil conjugate PPU. The part of the intensity distribution in the pupil conjugate PPU plane associated with the zero order diffracted beam is an image of the intensity distribution in the illumination system pupil IPU of the illumination system IL. For example, the aperture arrangement PD is arranged at or substantially at a plane comprising the pupil conjugate PPU of the projection system PS.

The projection system PS is arranged to capture not only the zero order diffracted beam, but also the first or first and higher order diffracted beams (not shown) by means of a lens or lens group L. In some embodiments, dipole illumination for imaging a line pattern extending in a direction perpendicular to the line may be used to exploit the resolution enhancing effect of dipole illumination. For example, the first order diffracted beam interferes with the corresponding zero order diffracted beam at the level of the wafer W to produce an image of the line pattern MP at as high a resolution and process window as possible (i.e., the available depth of focus is offset from the tolerable exposure dose). In some embodiments, astigmatic aberrations may be reduced by providing radiation emitters (not shown) in opposite quadrants of the illumination system pupil IPU. Furthermore, in some embodiments, astigmatic aberrations may be reduced by blocking the zeroth order beam in the pupil conjugate PPU of the projection system associated with the radiation pole in the opposite quadrant. This is described in more detail in US 7,511,799B 2 (which is incorporated herein by reference in its entirety) granted on 3/31/2009.

With the aid of the second positioner PW and position sensor IF (e.g. an interferometric device, linear encoder or capacitive sensor), the substrate table WT can be moved accurately (e.g. so as to position different target portions C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor (which is not depicted in fig. 1B) can be used to accurately position the mask MA with respect to the path of the radiation beam B (e.g. after mechanical retrieval from a mask library, or during a scan).

In general, movement of the mask table MT may be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WT may be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner) the mask table MT may be connected to a short-stroke actuator only, or may be fixed. Mask MA and substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. Although the substrate alignment marks (as shown) occupy dedicated target portions, they may be located in spaces between target portions (referred to as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the mask MA, the mask alignment marks may be located between the dies.

The mask table MT and patterning device MA may be in a vacuum chamber V, where a vacuum robot IVR may be used to move a patterning device, such as a mask, into and out of the vacuum chamber. Alternatively, when the mask table MT and the patterning device MA are outside the vacuum chamber, various transport operations may be performed using an out-of-vacuum robot, similar to the in-vacuum robot IVR. Both in-vacuum and out-of-vacuum robots require calibration in order to smoothly transfer any payload (e.g., mask) to a stationary moving support of a transfer table.

The lithographic apparatus 100 and 100' can be used in at least one of the following modes:

1. in step mode, the support structure (e.g. mask table) MT and the substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam is projected onto a target portion C at one time (i.e. a single static exposure). The substrate table WT is then shifted in the X and/or Y direction so that a different target portion C can be exposed.

2. In scan mode, the support structure (e.g. mask table) MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam is projected onto a target portion C (i.e. a single dynamic exposure). The velocity and direction of the substrate table WT relative to the support structure (e.g. mask table) MT may be determined by the (de-) magnification and image reversal characteristics of the projection system PS.

3. In another mode, the support structure (e.g., mask table) MT is kept essentially stationary holding a programmable patterning device, and the substrate table WT is moved or scanned while a pattern imparted to the radiation beam is projected onto a target portion C. A pulsed radiation source SO may be employed and the programmable patterning device updated as required after each movement of the substrate table WT during a scan or in between successive radiation pulses. This mode of operation can be readily applied to maskless lithography that utilizes programmable patterning device, such as a programmable mirror array.

Combinations and/or variations on the above described modes of use or entirely different modes of use may also be employed.

In a further embodiment, the lithographic apparatus 100 comprises an Extreme Ultraviolet (EUV) source configured to generate an EUV radiation beam for EUV lithography. Generally, an EUV source is configured in a radiation system, and a corresponding illumination system is configured for conditioning an EUV radiation beam of the EUV source.

FIG. 2 shows the lithographic apparatus 100 in more detail, the lithographic apparatus 100 comprising a source collector apparatus SO, an illumination system IL and a projection system PS. The source collector apparatus SO is constructed and arranged such that a vacuum environment can be maintained in the enclosure 220 of the source collector apparatus SO. The EUV radiation emitting plasma 210 may be formed by a discharge-generating plasma source. EUV radiation may be produced from a gas or vapor, such as xenon, lithium vapor, or tin vapor, in which a very hot plasma 210 is generated to emit radiation in the EUV range of the electromagnetic spectrum. The very hot plasma 210 is generated by, for example, an electrical discharge that causes at least a partially ionized plasma. For efficient generation of radiation, partial pressures of Xe, Li, Sn vapor, e.g. 10Pa, or any other suitable gas or vapor may be required. In some embodiments, a plasma of excited tin (Sn) is provided to produce EUV radiation.

Radiation emitted by the thermal plasma 210 is transferred from the source chamber 211 into the collector chamber 212 via an optional gas barrier or contaminant trap 230 (also referred to as a contaminant barrier or foil trap in some cases), the gas barrier or contaminant trap 230 being positioned in or behind an opening in the source chamber 211. The contaminant trap 230 may include a channel structure. The contaminant trap 230 may also include a gas barrier or a combination of a gas barrier and a channel structure. Further indicated herein are contaminant traps 230 (or contaminant barriers) comprising at least a channel structure.

The collector chamber 212 may comprise a radiation collector CO, which may be a so-called grazing incidence collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. Radiation passing through the collector CO may be reflected by the grating spectral filter 240 to be focused in the virtual source point IF. The virtual source point IF is usually referred to as the intermediate focus, and the source collector device is arranged such that the intermediate focus IF is located at or near the opening 219 in the enclosing structure 220. The virtual source point IF is an image of the radiation emitting plasma 210. The grating spectral filter 240 is particularly useful for suppressing Infrared (IR) radiation.

The radiation then passes through an illumination system IL, which may comprise a facet field mirror device 222 and a facet pupil mirror device 224 arranged to provide a desired angular distribution of the radiation beam 221 at patterning device MA and to provide a desired uniformity of the radiation intensity at patterning device MA. When the radiation beam 221 is reflected at the patterning device MA, which is held by the support structure MT, the patterned beam 226 is formed and the patterned beam 226 is imaged by the projection system PS via reflective elements 228, 229 onto a substrate W held by the wafer or substrate table WT.

There may typically be more elements in the illumination optics IL and projection system PS than shown. Depending on the type of lithographic apparatus, a grating spectral filter 240 may optionally be present. Furthermore, there may be more mirrors than shown in fig. 2, for example there may be one to six additional reflective elements in the projection system PS relative to that shown in fig. 2.

Collector optic CO as shown in fig. 2 is depicted as a nested collector with grazing incidence reflectors 253, 254, and 255, merely as an example of a collector (or collector mirror). Grazing incidence reflectors 253, 254 and 255 are arranged axisymmetrically about optical axis O and collector optics CO of this type are preferably used in conjunction with a discharge producing plasma source, commonly referred to as a DPP source.

Exemplary lithography Unit

FIG. 3 illustrates a lithography unit 300, sometimes referred to as a lithography unit (lithocell) or cluster, according to some embodiments. The lithographic apparatus 100 or 100' may form part of a lithographic cell 300. Lithography unit 300 may also include one or more apparatuses for performing pre-exposure and post-exposure processes on a substrate. Typically, these apparatuses include a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a cooling plate CH, and a baking plate BK. The substrate handler or robot RO picks up substrates from the input/output ports I/O1, I/O2, moves them between different processing apparatuses and transfers them to the loading station LB of the lithographic apparatus 100 or 100'. These devices (generally referred to as tracks) are under the control of a track control unit TCU, which itself is controlled by a supervisory control system SCS, which also controls the lithographic apparatus via a lithographic control unit LACU. Thus, different equipment may be operated to maximize throughput and processing efficiency.

Exemplary substrate stage

FIG. 4 shows a perspective schematic view of a substrate table 400 according to some embodiments. In some embodiments, the substrate table comprises a substrate table 402, a support block 404, and one or more sensor structures. In some embodiments, the substrate table 402 includes a chuck (e.g., an electrostatic chuck) for holding the substrate 408. In some embodiments, each of the one or more sensor structures 406 includes a Transmissive Image Sensor (TIS) plate. A TIS plate is a sensor unit that includes one or more sensors and/or markers for use in a TIS sensing system for accurately positioning a wafer with respect to the position of a projection system (e.g., projection system PS, fig. 1) and a mask (e.g., mask MA, fig. 1) of a lithographic apparatus (e.g., lithographic apparatus 100, fig. 1). The TIS plate is shown here for illustration. Embodiments herein are not limited to a particular sensor. The substrate table 402 is disposed on a support block 404. One or more sensor structures 406 are disposed on the support block 404. In some embodiments, the substrate 408 is disposed on the substrate table 402 when the substrate table 400 supports the substrate 408.

Exemplary substrate stage

The above-described mesas (e.g., the wafer table WT in fig. 1A and 1B, the substrate mesa 402 in fig. 4) may have a flatness tolerance of only tens of microns. Wafers that are relatively thin (e.g., <1mm thick) compared to the width of their surface area (e.g., >100mm) are particularly sensitive to substrate table non-planarity. Burls on the order of tens of microns on the substrate table may warp the substrate sufficiently to adversely affect subsequent photolithography and metrology processes performed on the substrate-after all, the critical dimensions of features in semiconductor devices may approach the sub-nanometer range.

The substrate table is typically coated with a cemented carbide (e.g., chromium nitride, titanium nitride, etc.) to protect the surface of the mesa. The coating reduces maintenance requirements and extends the service life of the assembly. To achieve the flatness tolerances required for the lithography and metrology processes, the substrate table is subjected to one or more planarization/polishing processes. One example of a planarization process is ion beam planarization (IBF). Some of the problems with IBF include process length (e.g., multiple passes over several days) and ion beam diameter. The ion beam diameter may not be small enough to be used for microscopic projections on the order of tens of microns on the surface of the platen. Embodiments of the present disclosure provide micromanipulator structures and operations to quickly and accurately remove microscopic protrusions, thereby saving costs due to manufacturing and maintenance time. The construction and operation of the micromanipulator can also be varied for precise deposition, rather than removal, of material.

FIG. 5 illustrates a schematic diagram of a micromanipulator arrangement 500 according to some embodiments. In some embodiments, the micromanipulator arrangement 500 comprises a stage 502, a metrology device 504, a material removal device 506, and an actuator 508. The metrology apparatus 504 includes a radiation source 510, an optical system 512, and a detector 514. Material removal device 506 includes an elongated element 516 and a pointed element 518. In some embodiments, the pointed element 518 is disposed at an end of the elongated element 516. The material removal device 506 is supported by an actuator 508. In some embodiments, the actuator 508 may support the material removal device 506 in a cantilevered arrangement. The connection between the material removal device 506 and the actuator 508 may include a hinged structure.

In some embodiments, radiation source 510 generates radiation 520. The platform 502 may support an object 522. The object 522 may be, for example, a wafer stage, a jig, or the like. A portion 524 of the object 522 may protrude from a planar surface (e.g., a surface for supporting a wafer) of the object 522. Portion 524 may be at least a portion of a burl or bubble, for example, randomly formed during a manufacturing process (e.g., a coating process), or some other minor defect. Optical system 512 directs radiation 520 toward object 522. Radiation scattered by object 522 and/or portion 524 is received by detector 514. The detector 514 generates and outputs data based on the received radiation. The data includes the location of the portion 524. In some embodiments, detector 514 comprises an image capture device (e.g., a camera). In this case, the data also includes an image of object 522 and/or portion 524.

To accurately target minute defects on the object 522, embodiments of the present disclosure employ actuators with high precision motion. In some embodiments, the minimum step of movement of actuator 508 may move material removal device 506 less than about 1 micron. In some embodiments, the minimum step of movement of actuator 508 may move material removal device 506 less than about 0.5 microns. In some embodiments, the minimum step of movement of actuator 508 may move material removal device 506 less than about 0.1 microns.

In some embodiments, actuator 508 may move material removal device 506 such that sharp element 518 is disposed at the location of portion 524. Using actuator 508, material removal device 506 may exert a force on portion 524 with pointed element 518 to remove portion 524 from object 522. Portion 524 comprises the same material (e.g., material of the surface coating) as the flat portion of the surface of object 522. For example, at least a portion of object 522 and portion 524 may include chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide. In this case, the force exerted by the sharp element 518 on the portion 524 is sufficient to remove the chromium nitride or titanium nitride. Since the coating material, such as chromium nitride, is relatively hard, the sharp element 518 may be depressed or otherwise damaged by the high force. Thus, in some embodiments, the pointed element 518 comprises tungsten, tungsten carbide, diamond, ruby, or other strong material.

As described above, when the IBF method is used, projection having a sufficiently small size may cause difficulty. Embodiments in the present disclosure may be used to remove small protrusions of an object. For example, in some embodiments, the dimension of portion 524 is less than about 200 microns. In some embodiments, the dimension of portion 524 is less than about 100 microns. In some embodiments, the dimension of portion 524 is less than about 50 microns. In some embodiments, the dimension of portion 524 is less than about 20 microns.

Thus, the micromanipulator arrangement 500 may be used to precisely position and effectively remove trace micro-defects that may have been left behind by other planarization processes (e.g., IBF). Embodiments of the present disclosure may be applicable, for example, where performing an IBF procedure is too time consuming to remove a small number of tiny defects. In the case of a wafer stage, a few residual defects still need to be removed because of the precision required by the lithographic process. The micromanipulator arrangement 500 meets this need without the need for lengthy planarization processes.

With some modifications, the micromanipulator device 500 can be used for precise deposition of materials, such as dispensing droplets of binding agent (e.g., micro-repair, repair). In some embodiments, the material removal device 506 may be replaced with a material dispensing device 526. The material dispensing device 526 includes an elongated conduit 528 and a dispensing end 530. The dispensing end 530 is disposed at the end of the elongated conduit 528. In some embodiments, the material dispensing device 526 is supported by the actuator 508. The relationship and interaction between the material dispensing device 526 and the actuator 508 is the same as that described above for the material removal device 506 and the actuator 508. Thus, the material dispensing device 526 is capable of the same types of motion and precision as described above for the material removal device 506. The metrology device 504 and the elements therein are used to direct radiation toward a target on the object. The target may be a location where a repair is to be made.

In some embodiments, the material dispensing device 526 can be used to dispense material 532 onto the object 522 outward from the dispensing end 530. Material 532 may be, for example, a bonding agent for precision repair and repair. In some embodiments, the size of the material 532 dispensed by the material dispensing device 526 is less than about 100 microns. In some embodiments, the size of the material 532 dispensed by the material dispensing device 526 is less than about 50 microns. In some embodiments, the size of the material 532 dispensed by the material dispensing device 526 is less than about 20 microns.

It may sometimes be desirable to measure the removal protrusion of a planar surface, for example, to determine the cause of the protrusion formed during processing of the planar surface. FIG. 6 illustrates a schematic diagram of a metrology system 600, according to some embodiments. In some embodiments, metrology system 600 includes a stage 602, a radiation source 604, an optical system 606, a detector 608, a material removal device 610, and an actuator 612. The material removal device includes an elongated element 614 and a sharp element 616. In some embodiments, metrology system 600 further includes a metrology device 618 and an actuator 620.

In some embodiments, radiation source 604 generates radiation 622. The platform 602 may support an object 624. Object 624 may be, for example, a wafer stage, a chuck, etc. A portion 626 of object 624 can protrude from a planar surface (e.g., a surface for supporting a wafer) of object 624. Portion 626 may be at least a portion of a knob or bubble, for example, randomly formed during a manufacturing process (e.g., a coating process), or some other minor defect. Optical system 606 directs radiation 622 toward object 624. Radiation scattered by object 624 and/or portion 626 is received by detector 608. The detector 608 generates data based on the received radiation and outputs the data. The data includes the location of portion 626. In some embodiments, detector 608 comprises an image capture device (e.g., a camera). In this case, the data also includes an image of object 624 and/or portion 626. The accuracy of the movement of the actuator 612 and the material removal device 610 is the same as described above for the actuator 508 and the material removal device 506 (fig. 5) for the reasons discussed above with reference to fig. 5.

In some embodiments, actuator 612 may move material removal device 610 such that sharp element 616 is disposed at the location of portion 626. Using actuator 612, material removal device 610 may exert a force on portion 626 with pointed element 616 to remove portion 626 from object 624. Portion 626 comprises the same material (e.g., a surface-coated material) as the flat portion of the surface of object 624. For example, at least a portion of object 624 and portion 626 may comprise chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide. In this case, the force exerted by the pointed element 616 on the portion 626 is sufficient to remove the chromium nitride or titanium nitride. Since the coating material, such as chromium nitride, is relatively hard, the sharp element 616 may be depressed or otherwise damaged by the strong force. Thus, in some embodiments, the pointed element 616 comprises tungsten, tungsten carbide, diamond, ruby, or other strong material. Possible dimensions of portion 626 are the same as those described above for portion 524 (fig. 5) for the reasons discussed above with reference to fig. 5.

To measure portion 626 after portion 626 has been removed from object 624, in some embodiments, actuator 612 may convey portion 626 to measurement device 618. In some embodiments, metrology device 618 may determine the properties of portion 626 by performing one or more of the following: scanning electron microscopy, tunneling electron microscopy, mass spectrometry, cathodoluminescence spectroscopy, and energy dispersive X-ray spectroscopy. If it is difficult for actuator 612 to transfer portion 626 directly to measurement device 618 (e.g., due to distance), in some embodiments, actuator 612 may transfer portion 626 to actuator 620. Actuator 620 can include a platform and/or manipulator element (e.g., gripper, robotic arm, etc.) for receiving portion 626 from actuator 612.

Accordingly, the metrology system 600 incorporates the structure and functionality described with reference to the micromanipulator assembly 500 (FIG. 5) for precise positioning and efficient removal of micro-defects that may have been left over by other planarization processes. The metrology system 600 further provides characterization capabilities to analyze micro-defects after removal from the master.

In some embodiments, a material removal device with a sharp element may be used for metrology measurements, for example, when used as a cantilever in conjunction with Atomic Force Microscope (AFM) operations. FIG. 7 illustrates a system for performing metrology measurements and accurate removal of material, in accordance with some embodiments. In some embodiments, the system includes a metrology apparatus 700, the metrology apparatus 700 including a stage 702, a radiation source 704, a detector 706, a processor 708, and a cantilever 710, the cantilever 710 including a sharp element 712.

In some embodiments, the platform 702 may support an object 714. The object 714 may be, for example, a wafer stage, a work table, a jig, or the like. A portion 716 of the object 714 may protrude from a planar surface (e.g., a surface for supporting a wafer) of the object 714. Portion 716 may be at least a portion of a knob or bubble, for example, randomly formed during a manufacturing process (e.g., a coating process), or some other minor defect.

In some embodiments, radiation source 704 generates radiation 718. The radiation source 704 may direct radiation 718 towards the cantilever 710, e.g., onto a reflective portion of the cantilever 710. Radiation reflected from cantilever 710 may then be incident on detector 706, i.e., detector 706 may receive radiation scattered by cantilever 710. The properties of the radiation scattered by cantilever 710 (e.g., direction of propagation, spot location on the detector) are based on the state of cantilever 710 (e.g., deflection state). The detector 704 may be a position sensitive photodetector. Thus, a change in state (e.g., deflection) of the cantilever 710 can be sensed by the detector 706.

In some embodiments, cantilever 710 may deflect as it scans across the surface of object 714. To allow scanning, the position of object 714 may be adjusted relative to cantilever 710. For example, one or more actuators capable of translational and/or rotational motion in one, two, or three dimensions may be used to adjust the position of the platform 702 supporting the object 714. The cantilever 710 may be actuated instead of or in addition to the actuation platform 702. Initially, the sharp element 712 of the cantilever 710 may be brought into contact with the object 714 using a small force so that the object 714 is not damaged during scanning. As the position of the object 714 is adjusted, the cantilever 710 will not experience further deflection if the surface of the scanned object 714 is very smooth and flat. However, when the sharp element 712 contacts the portion 716, the cantilever 710 may deflect an amount that is based on one or more properties (e.g., height, volume) of the portion 716. The detector 704 may generate a detection signal based on the received radiation. The detection signal may then be used to determine one or more properties of the portion 716, such as area, height, volume, location, and the like. Processor 708 may receive the detection signal to determine one or more properties of portion 716. Processor 708 may also generate an image 720 for a visual representation of one or more properties of portion 716. In this manner, metrology measurements may be taken of the object 714.

In some embodiments, the metrology device 700 may introduce a force between the pointed element 712 and the portion 716 to remove the portion 716 from the object 714. Using the motion of platform 702, pointed element 712 may exert a force on portion 524 to remove portion 716 from object 714. The portion 716 comprises the same material (e.g., material of the surface coating) as the flat portion of the surface of the object 714. For example, at least a portion of object 714 and portion 716 may include chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide. In this case, the force exerted by the pointed element 712 on the portion 716 is sufficient to remove the chromium nitride or titanium nitride. Since the coating material may be quite hard, the sharp elements 712 may be dented or otherwise damaged by the strong force. Thus, in some embodiments, the pointed element 712 comprises tungsten, tungsten carbide, diamond, ruby, or other strong material.

In some embodiments, the position sensors and actuators may be highly accurate, for example, down to submicron levels in AFM type measurements. For example, in some embodiments, the minimum step size of movement of the platform 702 may be less than about 100 nm. In some embodiments, the minimum step size of movement of the platform 702 may be less than about 50 nm. In some embodiments, the minimum step size of movement of the platform 702 may be less than about 10 nm. In some embodiments, the minimum step size of movement of the platform 702 may be less than about 1 nm. In some embodiments, the minimum step size of movement of the platform 702 may be less than about 0.1 nm. In addition, AFM type measurements are capable of resolving details of the measured object at the submicron level. For example, in some embodiments, the dimension of portion 716 is less than about 1000 nm. In some embodiments, the dimension of portion 716 is less than about 500 nm. In some embodiments, the dimension of portion 716 is less than about 100 nm. In some embodiments, the dimension of portion 716 is less than about 50 nm. In some embodiments, the dimension of portion 716 is less than about 10 nm. In some embodiments, the dimension of portion 716 is less than about 1 nm. In some embodiments, the dimension of portion 716 is less than about 0.1 nm. The metrology apparatus 700 may use the cantilever 710 and the sharp element 712 to remove the portion 716 having the dimensions described above.

In some embodiments, metrology tool 700 may perform metrology measurements and material removal in situ. For example, the system may perform the determination of one or more properties of the portion 716 and the removal of the portion 716 in situ. The metrology apparatus 700 may perform in-situ functions because the cantilever 710 serves as both a metrology probe and a material removal device. For example, the process of removing portion 716 from object 714 may use the operations described above to remove material from portion 716. Since the sharp element 712 is already in contact with the portion 716, in-situ metrology measurements may be performed on the portion 716 during the removal operation. If the in situ measurement indicates that the removal was not successful (e.g., sufficient material was not removed), a subsequent removal process may be performed using the updated force parameters based on one or more properties of the remaining portion of the portion 716 as determined by the in situ measurement.

In some embodiments, a laser may be used to ablate or otherwise remove unwanted material from a surface. FIG. 8 illustrates a system 800 for performing metrology measurements and accurate removal of material, in accordance with some embodiments. In some embodiments, the system 800 includes a stage 802, an illumination system 804, a metrology system 806, and a controller 808. The controller 808 may be a processor. The illumination system 804 can include a radiation source 810 and one or more light directing elements 812. The one or more light directing elements 812 may be, for example, actuated mirrors, galvanometers, or the like.

In some embodiments, the platform 802 may support an object 814. The object 814 may be, for example, a wafer stage, a work table, a jig, or the like. A portion 816 of the object 814 can protrude from a planar surface (e.g., a surface for supporting a wafer) of the object 814. The portion 816 may be at least a portion of a knob or bubble, for example, randomly formed in a manufacturing process (e.g., a coating process), or some other minor defect.

In some embodiments, the illumination system 804 generates a radiation beam 818 using the radiation source 810. The one or more light directing elements 812 may direct the beam of radiation 818 toward the object 814. The radiation source 810 may be a laser device, such as a CO2 laser, a Yttrium Aluminum Garnet (YAG) laser, and/or variations thereof. The beam of radiation 818 can include coherent radiation. The beam 818 may be pulsed or continuous wave. The beam 818 may include an intensity suitable to ablate the material of the portion 816. In some embodiments, the portion 816 comprises the same material (e.g., a surface-coated material) as the planar portion of the surface of the object 814. For example, at least a portion of object 814 and portion 816 may include chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide.

In some embodiments, the material of object 814 and/or portion 816 may have a wavelength-dependent behavior that affects ablation. The radiation source 810 may have a selectable wavelength in order to select a desired wavelength for the material. A non-limiting example of a means for selectively adjusting the wavelength is a photonic frequency doubler. The radiation beam 818 may include wavelengths in the ultraviolet range (e.g., 100-400 nm).

In some embodiments, metrology system 806 can determine one or more properties of portion 816, such as area, height, volume, location, material composition, and the like. Metrology system 806 can include an optical measurement device. Some non-limiting examples of optical measurement devices include interferometers and optical profilometers. In some embodiments, it may be particularly useful if the optical measurement device is capable of determining the height of portion 716 (perpendicular to the surface of object 814). The metrology system 806 can generate input data based on the determined one or more properties of the portion 816. The input data may be received at the controller 808. The controller 808 may then use the input data to control the ablation process, for example, by adjusting parameters of the illumination system 804 (e.g., beam intensity, pulse energy, repetition rate, average power of the beam, etc.) and positioning the portion 816 in the path of the radiation beam 818. Parameters of the illumination system 804 may be adjusted to ablate the particular material composition identified by the metrology system 806. Parameters of the illumination system 804 may be adjusted by the controller 808 to ablate only the minimum amount of material needed to achieve the desired flatness consistency of the surface of the object 814. This avoids unnecessary thermal energy build up at the ablation site leading to surface deformation. In some embodiments, the measurement of the object 814 and the removal of the portion 816 may be automated by using the metrology system 806, the controller 808, and the illumination system 804 as described above and allowing the system 800 to scan the entire span of the surface of the object 814. That is, the system 800 may automatically remove portions of the object 814 over the entire span of the surface of the object 814.

In some embodiments, the input data may include instructions for the controller 808 to use to adjust parameters of the illumination system 804. In some embodiments, the input data may include data regarding the detection of measurements performed by the metrology system 806. In this case, the input data may then be processed by the controller 808 to generate instructions for adjusting parameters of the illumination system 804.

In some embodiments, based on the input data, the controller 808 may actuate any combination of the stage 802, the illumination system 804, and the one or more light directing elements 812 to position the portion 816 in the path of the beam 818. One or more actuators capable of translational and/or rotational motion in one, two, or three dimensions may be used to adjust the position of the platform 802 and/or the illumination system 804.

In some embodiments, the position sensors and actuators may be highly accurate, e.g., down to submicron levels. For example, in some embodiments, the minimum step size of movement of the platform 802 and/or the illumination system 804 may be less than about 500 nm. In some embodiments, the minimum step size of movement of the platform 802 and/or the illumination system 804 may be less than about 100 nm. In addition, AFM type measurements are capable of resolving details of the measured object at the submicron level. For example, in some embodiments, the dimension of the portion 816 is less than about 1000 nm. In some embodiments, the dimension of the portion 816 is less than about 500 nm. In some embodiments, the dimension of the portion 816 is less than about 100 nm. The system 800 may remove the portion 816 having the dimensions described above using the laser removal operation described herein.

In some embodiments, the controller 808 may adjust parameters of the illumination system 804 such that the power of the radiation beam 818 is just sufficient to sever chemical bonds of the portion 816 without completely ablating the portion 816. The separated portion 816 may then be purged (e.g., a solution bath, a gas spray, etc.). Using this technique, heating of the object 814 may be further reduced.

In some embodiments, elements described with reference to a given figure may be implemented in embodiments described with reference to another figure. For example, the cantilever measurement system of FIG. 7 may be used as the metrology system of FIG. 8. Doing so may increase the accuracy of the metrology system 806 to that of an AFM system, while potentially sacrificing the measurement speed provided by the optical metrology system. One skilled in the art will appreciate that other combinations of elements from two or more of the figures are contemplated.

Fig. 9 illustrates method steps for performing the functions described herein, in accordance with some embodiments. At step 902, a radiation beam may be generated using an illumination system. At step 904, a beam of radiation may be directed toward a portion of the object. At step 906, the portion of the object may be ablated using the radiation beam. At step 908, one or more properties of the portion of the object may be determined using the metrology system. At step 910, input data may be generated using a metrology system. One or more properties of the portion of the object may be as previously described (e.g., location, size, height, etc.). At step 912, input data may be received at the controller. In step 914, ablation may be controlled based on the input data. For example, controlling may comprise positioning the portion of the object in the path of the radiation beam and adjusting a parameter of the illumination system based on the input data, wherein the parameter comprises an average power of the beam.

The method steps of fig. 9 may be performed in any conceivable order, and not all steps need be performed. Moreover, the method steps of FIG. 9 described above reflect examples of steps only, and are not limiting. That is, further method steps and functions may be envisaged based on the embodiments described with reference to fig. 1 to 8.

The embodiments may be further described using the following clauses:

1. a system for removing a portion of an object, the system comprising:

metrology apparatus, comprising:

a cantilever comprising a sharp element, wherein the cantilever is configured to deflect when the sharp element contacts the portion of the object;

a platform configured to support the object and position the object relative to the cantilever;

an illumination system configured to generate radiation and direct the radiation towards the cantilever, wherein a property of the radiation scattered by the cantilever is based on a deflection state of the cantilever;

a detector configured to receive scattered radiation and to generate a signal based on the received scattered radiation; and

a processor configured to receive the signal and determine one or more properties of the portion of the object,

wherein the metrology device is configured to use motion of the platform to introduce a force between the sharp element and the portion of the object to remove the portion of the object, and the force is selected based on a size of the portion of the object.

2. The system of clause 1, wherein the sharp element comprises tungsten, tungsten carbide, diamond, or ruby.

3. The system of clause 1, wherein the object comprises a wafer stage and the portion of the object comprises at least a portion of a burl.

4. The system of clause 1, wherein the portion of the object comprises a material comprising chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide, and the force is sufficient to remove the material.

5. The system of clause 1, wherein the minimum step size of movement of the platform is less than about 50 nm.

6. The system of clause 1, wherein the minimum step size of movement of the platform is less than about 10 nm.

7. The system of clause 1, wherein the portion of the object is less than about 100nm in size.

8. The system of clause 1, wherein the portion of the object is less than about 10nm in size.

9. The system of clause 1, wherein the metrology system can perform determining the one or more properties of the portion of the object and removing the portion of the object in situ.

10. A system for removing a portion of an object, the system comprising:

a platform configured to support the object;

an illumination system configured to generate a beam of radiation and to direct the beam towards the portion of the object to ablate the portion of the object;

a metrology system configured to determine one or more properties of the portion of the object and generate input data based on the determined one or more properties, wherein the determined one or more properties include a position and an elevation of the portion of the object; and

a controller configured to perform operations comprising:

receiving the input data; and

controlling the ablation, wherein the controlling comprises positioning the portion of the object in a path of the beam and adjusting a parameter of the illumination system based on the input data, and the parameter comprises an average power of the beam.

11. The system of clause 10, wherein:

the determined one or more properties include a composition of a material of the portion of the object;

the material comprises chromium nitride, titanium nitride, diamond-like carbon, silicon or silicon carbide; and

the controller is further configured to adjust the parameter to ablate the material.

12. The system of clause 10, wherein the object comprises a wafer stage and the portion of the object comprises at least a portion of a burl.

13. The system of clause 10, wherein the beam comprises a wavelength between about 100 and 400 nm.

14. The system of clause 10, wherein the metrology system comprises an interferometer.

15. The system of clause 10, wherein the metrology system comprises an optical profiler.

16. The system of clause 10, wherein the system is configured to automatically remove the portion of the object over the entire span of the surface of the object.

17. The system of clause 10, wherein the adjusting further comprises adjusting the parameters of the illumination system such that chemical bonds of the portion of the object are severed without completely ablating the portion of the object.

18. A method, comprising:

generating a radiation beam;

directing the beam at a portion of an object;

ablating the portion of the object using the radiation beam;

determining one or more properties of the portion of the object using a metrology system;

generating, using the metrology system, input data based on the determined one or more properties, wherein the one or more properties include a position and an elevation of the portion of the object;

receiving the input data at a controller;

controlling the ablation, wherein the controlling comprises:

positioning the portion of the object in a path of the beam; and

adjusting a parameter of the illumination system based on the input data, wherein the parameter comprises an average power of the beam.

19. The method of clause 18, wherein the metrology system comprises an interferometer.

20. The method of clause 18, wherein the adjusting further comprises adjusting the parameters of the illumination system such that chemical bonds of the portion of the object are severed without completely ablating the portion of the object.

In some embodiments, the removed portion of the object may remain on the surface of the object as a result of any of the above-described removal processes. It will be appreciated by those skilled in the art that the removed residual portions of the object may be removed using cleaning techniques (e.g., bath of solution, blowing off by gas spray, vacuuming, etc.).

Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, LCDs, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms "wafer" or "die" herein may be considered as synonymous with the more general terms "substrate" or "target portion", respectively. The substrate referred to herein may be processed, before or after exposure, in for example a track unit (a tool that typically applies a layer of resist to a substrate and develops the exposed resist) or a metrology or inspection unit. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example in order to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers.

Although specific reference may have been made above to the use of various embodiments in the context of optical lithography, it will be appreciated that such embodiments may be used in other applications, for example imprint lithography, and where the context allows, are not limited to optical lithography. In imprint lithography, a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device can be pressed into a layer of resist provided to the substrate and the resist is then cured by applying electromagnetic radiation, heat, pressure or a combination thereof. After the resist is cured, the patterning device is moved out of the resist to leave a pattern therein.

It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present disclosure will be interpreted by the skilled artisan in light of the teachings herein.

Furthermore, the terms "radiation", "beam" and "light" as used herein may encompass all types of electromagnetic radiation, such as Ultraviolet (UV) radiation (e.g. having a wavelength λ of 365, 248, 193, 157 or 126nm), extreme ultraviolet (EUV or soft X-ray) radiation (e.g. having a wavelength in the range of 5-20nm, such as 13.5nm), or hard X-rays operating at less than 5nm, as well as particle beams, such as ion beams or electron beams. Generally, radiation having a wavelength between about 400 and about 700nm is considered visible radiation; radiation having wavelengths between about 780-3000nm (or greater) is considered IR radiation. UV refers to radiation having a wavelength of about 100-400 nm. In lithography, the term "UV" also applies to wavelengths that can be produced by mercury discharge lamps: line G436 nm; h line 405 nm; and/or I-line 365 nm. Vacuum UV line or VUV (i.e., UV absorbed by a gas) refers to radiation having a wavelength of about 100-200 nm. Deep Uv (DUV) generally refers to radiation in the wavelength range from 126nm to 428nm, and in some embodiments, excimer lasers may generate DUV radiation for use within a lithographic apparatus. It is to be understood that radiation having a wavelength, for example in the range of 5-20nm, relates to radiation having a specific wavelength band, at least part of which is in the range of 5-20 nm.

As used herein, the term "substrate" describes a material to which a layer of material is added. In some embodiments, the substrate itself may be patterned, and the material added thereon may also be patterned, or may remain unpatterned.

Although specific reference may be made in this text to the use of the disclosed embodiments in the manufacture of ICs, it should be explicitly understood that such apparatus and/or systems have many other possible applications. For example, it can be used to manufacture integrated optical systems, guidance and detection patterns for magnetic domain memories, LCD panels, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms "reticle," "wafer," or "die" herein should be considered as being replaced with the more general terms "mask," "substrate," and "target portion," respectively.

While specific embodiments of the disclosure have been described above, it will be appreciated that the disclosure may be practiced otherwise than as described. The description is not intended to be limiting.

It should be understood that the detailed description section, and not the summary and abstract sections, is intended to be used to interpret the claims. The summary and abstract sections may set forth one or more, but not all exemplary embodiments of the disclosure as contemplated by the inventors, and are therefore not intended to limit the disclosure and the appended claims in any way.

The present disclosure has been described above with the aid of functional building blocks illustrating the implementation of specific functions and relationships thereof. Boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

The foregoing description of the specific embodiments will so fully reveal the general nature of the disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein.

The breadth and scope of the claimed subject matter should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.