阅读说明：本技术 用于半导体处理腔室中的气体输送的设备和方法 (Apparatus and method for gas delivery in a semiconductor processing chamber ) 是由 文森特·基尔霍夫 法鲁克·冈果尔 费利克斯·拉比诺维奇 加里·凯伯斯 于 2018-05-31 设计创作，主要内容包括：用于在半导体处理系统中的气体输送的设备的实施方式使用具有多个气体通路的气体分配板,其中通路具有平均粗糙度小于或等于约10Ra的表面。在一些实施方式中,气体分配板具有一个或更多个内部流体通路,所述内部流体通路能够流体耦接至一个或更多个流体源,以提供对气体分配板的温度控制。在一些实施方式中,气体分配板具有至少一个内部空腔,内部空腔具有至少一个散热器,所述散热器可以围绕多个气体通路的至少一者,以至少部分地提供对气体分配板的温度控制。(Embodiments of an apparatus for gas delivery in a semiconductor processing system use a gas distribution plate having a plurality of gas passages, wherein the passages have a surface with an average roughness of less than or equal to about 10 Ra. In some embodiments, the gas distribution plate has one or more internal fluid passages that can be fluidly coupled to one or more fluid sources to provide temperature control of the gas distribution plate. In some embodiments, the gas distribution plate has at least one internal cavity with at least one heat sink that can surround at least one of the plurality of gas passages to at least partially provide temperature control of the gas distribution plate.)

1. An apparatus for gas delivery in a semiconductor processing system, comprising:

a gas distribution plate having a plurality of gas passages, at least one of the plurality of gas passages having a surface with a roughness of less than or equal to about 10 Ra.

2. The apparatus of claim 1, wherein the gas distribution plate is a blocker plate in a showerhead of the semiconductor processing system.

3. The apparatus of claim 1, wherein the gas distribution plate has an internal fluid passage around a perimeter of the gas distribution plate that is fluidly coupleable to a fluid source to provide temperature control of the gas distribution plate.

4. The apparatus of claim 1, wherein the gas distribution plate has at least one internal cavity surrounding at least one of the plurality of gas passages, the internal cavity being fluidly coupleable to a fluid source to provide temperature control of the gas distribution plate.

5. The apparatus of claim 1, wherein the gas distribution plate has at least one heat sink at least partially embedded therein and surrounding at least one of the plurality of gas passages.

6. The apparatus of claim 1, wherein at least one of the plurality of gas passages has a surface with a roughness of less than or equal to about 2 Ra.

7. The apparatus of claim 1, further comprising:

a flange engaged with a perimeter of the gas distribution plate to provide support for installation in the semiconductor processing system.

8. The apparatus of claim 7, wherein the gas distribution plate and the flange are joined by cold welding.

9. A processing chamber, comprising:

a chamber body having a substrate support disposed within an interior processing volume of the chamber body; and

a showerhead disposed within an interior processing volume of the chamber body opposite the substrate support, the showerhead comprising:

at least one gas distribution plate having a plurality of gas passages, at least one of the plurality of gas passages having a surface with a roughness of less than or equal to about 10 Ra; and

a flange engaged with a perimeter of at least one of the at least one gas distribution plate to provide support for a component mounted to the processing chamber.

10. The processing chamber of claim 9, wherein the flange and at least one of the at least one gas distribution plate are a single piece.

11. The processing chamber of claim 9, wherein at least one of the at least one gas distribution plate has an internal fluid passage around a perimeter of the at least one gas distribution plate that is fluidly coupleable to a fluid source to provide temperature control of the at least one gas distribution plate.

12. The processing chamber of claim 9, wherein at least one of the at least one gas distribution plate has at least one internal cavity surrounding at least one of the plurality of gas passages, the internal cavity being fluidly coupleable to a fluid source to provide temperature control of the at least one gas distribution plate.

13. The processing chamber of claim 9, wherein at least one of the at least one gas distribution plate has at least one heat sink at least partially embedded therein and surrounding at least one of the plurality of gas passages.

14. The processing chamber of claim 9, wherein at least one of the plurality of gas passages has a surface with a roughness less than or equal to about 2 Ra.

15. A method of forming a gas delivery apparatus, comprising the steps of:

providing a mandrel having a conductive base to form a gas distribution plate on the conductive base;

engaging at least one pin with the mandrel, the pin having an average surface roughness of less than or equal to about 10 Ra;

electroforming a nickel material onto the mandrel to form the gas distribution plate; and

removing the gas distribution plate from the mandrel.

Technical Field

Embodiments of the present disclosure generally relate to gas delivery in semiconductor processing chambers used in semiconductor manufacturing systems.

Background

Conventional showerheads used in semiconductor processing chambers (e.g., deposition chambers, etch chambers, or the like) typically include a gas delivery device or "showerhead" that flows gases into the semiconductor processing chamber. These gases are used for various processing purposes, such as depositing materials onto substrates placed in a processing chamber. The delivery gas parameters, such as pressure, temperature, and velocity, affect the processing of the substrate in the chamber. The flow rate (flow rate) and the flow dynamics through the showerhead influence the transport gas parameters. Current manufacturing techniques have limited ability to establish a smooth fluid flow path through the showerhead due to the small size of the path.

Accordingly, the inventors provide improved methods for enhanced gas delivery in semiconductor processing chambers.

Disclosure of Invention

Embodiments of an apparatus for gas delivery in a semiconductor processing system are provided herein. In some embodiments, an apparatus for gas delivery in a semiconductor processing system includes a gas distribution plate having a plurality of gas passages, at least one of the plurality of gas passages having a surface with a roughness less than or equal to about 10 Ra.

In some embodiments, a processing chamber includes a chamber body having a substrate support disposed within an interior processing volume of the chamber body and a showerhead disposed within the interior processing volume of the chamber body opposite the substrate support, wherein the showerhead includes a gas distribution plate having a plurality of gas passages, at least one of the plurality of gas passages having a surface with a roughness less than or equal to about 10Ra, and a flange engaged with a periphery of the gas distribution plate to provide support for components mounted to the processing chamber.

In some embodiments, a method of forming a gas delivery apparatus comprises the steps of: providing a mandrel (mandrel) having an electrically conductive base to form a gas distribution plate on the electrically conductive base, engaging at least one pin with the mandrel, the pin having an average surface roughness of less than or equal to about 10Ra, electroforming a nickel material onto the mandrel to form the gas distribution plate, removing the gas distribution plate from the mandrel, and electroforming the gas distribution plate to the flange to form the gas delivery apparatus.

Drawings

Embodiments of the present disclosure, briefly summarized above and discussed in more detail below, may be understood with reference to illustrative embodiments of the disclosure, which are illustrated in the accompanying drawings. However, the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

Fig. 1 illustrates a schematic cross-sectional view of a processing chamber according to some embodiments of the present principles.

Fig. 2 illustrates a schematic cross-sectional view of an apparatus for gas delivery according to some embodiments of the present principles.

Fig. 3 illustrates a schematic cross-sectional view of a mandrel with a non-conductive permanent pin according to some embodiments of the present principles.

Fig. 4a illustrates a schematic cross-sectional view of a mandrel with a non-conductive permanent pin and tube (tube) according to some embodiments of the present principles.

Figure 4b illustrates a schematic cross-sectional view of a mandrel with non-conductive permanent pins and a tubular after forming an apparatus for gas delivery according to some embodiments of the present principles.

Fig. 5 illustrates a schematic cross-sectional view of a mandrel with a non-conductive disposable pin according to some embodiments of the present principles.

Fig. 6 illustrates a schematic cross-sectional view of a mandrel with conductive pins according to some embodiments of the present principles.

Fig. 7 is a flow diagram illustrating a method of forming an apparatus for gas delivery according to some embodiments of the present principles.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. For clarity, the figures are not drawn to scale and may be simplified. Elements and features of one embodiment may be advantageously incorporated in other embodiments without further elaboration.

Detailed Description

The inventors have observed that conventional gas delivery devices have gas passages or "holes" with high surface roughness. Gas turbulence caused by surface roughness within the via can lead to undesirable process results (such as non-uniform deposition and etching). Embodiments of the present principles advantageously provide a gas delivery apparatus with reduced gas passage surface roughness, which results in less turbulent gas delivery during processing. In addition, the gas delivery apparatus may also advantageously control the thermal properties of the gas delivery apparatus during processing to provide higher quality products. In some embodiments, the apparatus may advantageously provide a gas distribution plate having multiple passages that serve as a "face plate" for a showerhead, the multiple passages providing smoother and more uniform gas flow rates, and in some embodiments, more uniform temperature control. In some embodiments, the apparatus may advantageously provide a gas distribution plate having a plurality of passages that provide smoother and more uniform gas flow rates, and in some embodiments, more uniform temperature control, for use as a "blocker plate" for a showerhead.

Fig. 1 illustrates a processing chamber 100 suitable for use in conjunction with an apparatus for gas delivery according to some embodiments of the present principles. For example, other suitable chambers include any chamber that incorporates a gas delivery apparatus (such as, for example, a showerhead) to perform a substrate fabrication process.

In some embodiments, the processing chamber 100 generally includes a chamber body 102, the chamber body 102 defining an interior process volume 104 and an exhaust volume 106. For example, the interior processing volume 104 may be defined between a substrate support 108 and one or more gas inlets (such as a showerhead 114 and/or nozzles provided at predetermined locations), the substrate support 108 being disposed within the processing chamber 100 for supporting a substrate 110 thereon during processing. For example, an exhaust volume may be defined between the substrate support 108 and the bottom of the processing chamber 100.

The substrate support 108 generally includes a body 143, the body 143 having a substrate supporting surface 141 for supporting the substrate 110 thereon. In some embodiments, the substrate support 108 may include an apparatus (not shown) that holds or supports the substrate 110 on a surface of the substrate support 108, such as an electrostatic chuck, a vacuum chuck, a substrate holding clamp (substrate retainingcramp), or the like.

In some embodiments, the substrate support 108 may include a Radio Frequency (RF) bias electrode 168. The RF bias electrode 168 can be coupled to one or more RF bias power sources (one RF bias power source 148A and one matching network 146A shown in fig. 1) through one or more corresponding matching networks. One or more bias power sources can generate up to 12000W at a frequency of about 2MHz, or about 13.56MHz, or about 60 MHz. In some embodiments, two bias power sources may be provided for coupling RF power to the RF bias electrodes through respective matching networks at frequencies of about 2MHz and about 13.56 MHz. In some embodiments, three bias power sources may be provided for coupling RF power to the RF bias electrodes through respective matching networks at frequencies of about 2MHz, about 13.56MHz, and about 60 MHz. The at least one bias power source may provide continuous power or pulsed power. In some embodiments, the bias power source may be a DC source or a pulsed DC source.

In some embodiments, the substrate support 108 may include one or more mechanisms for controlling the temperature of the substrate supporting surface 141 and the substrate 110 disposed thereon. For example, one or more channels (not shown) may be provided to define one or more flow paths below the substrate support surface to flow a heat transfer medium similar to that described below with respect to the showerhead 114.

One or more gas inlets (e.g., the showerhead 114) may be coupled to a gas supply 116 for providing one or more process gases into the interior processing volume 104 of the processing chamber 100. Although a showerhead 114 is illustrated, additional gas inlets may be provided (such as nozzles or inlets disposed in the ceiling or on the sidewalls of the processing chamber 100, or nozzles or inlets disposed at other locations suitable for providing gases to the processing chamber 100 (such as the pedestal of the processing chamber, the periphery of the substrate support, or the like)).

In some embodiments, one or more RF plasma power sources (one RF plasma power source 148B is shown) may be coupled to the processing chamber 100 through one or more matching networks 146B to provide power for processing. In some embodiments, the process chamber 100 may utilize capacitively coupled RF power provided to an upper electrode proximate to an upper portion of the process chamber 100. The upper electrode may be a conductor in an upper portion of the processing chamber 100 or formed at least in part by one or more of the ceiling 142, the showerhead 114, or the like, and made of a suitable conductive material. For example, in some embodiments, one or more RF plasma power sources 148B may be coupled to a conductive portion of the ceiling 142 of the processing chamber 100 or to a conductive portion of the showerhead 114. The top plate 142 may be substantially flat, although other types of top plates (such as dome-shaped top plates or the like) may also be utilized. The one or more plasma sources are capable of producing up to 5000W at a frequency of about 2MHz and/or about 13.56MHz or higher, such as 27MHz, and/or 60MHz, and/or 162 MHz. In some embodiments, two RF power sources may be coupled to the upper electrode through respective matching networks for providing RF power at frequencies of about 2MHz and about 13.56 MHz. Alternatively, one or more RF power sources may be coupled to an inductive coil element (not shown) disposed proximate to a ceiling of the processing chamber 100 to form a plasma having inductively coupled RF power.

In some embodiments, the internal processing volume 104 may be fluidly coupled to an exhaust system 120. The exhaust system 120 may facilitate uniform flow of exhaust gases from the internal process volume 104 of the process chamber 100. The exhaust system 120 generally includes a pumping plenum 124 and a plurality of conduits (not shown) coupling the pumping plenum 124 to the interior process volume 104 of the process chamber 100. The conduit has an inlet 122 coupled to the internal process volume 104 (or, in some embodiments, the exhaust volume 106) and has an outlet (not shown) fluidly coupled to the pumping plenum 124. For example, the conduit may have an inlet 122 disposed in a lower region of the sidewall or floor of the processing chamber 100. In some embodiments, the inlets are substantially equally spaced.

A vacuum pump 128 may be coupled to the pumping plenum 124 via the pumping port 126 for pumping exhaust gases out of the processing chamber 100. The vacuum pump 128 may be fluidly coupled to an exhaust outlet 132 for directing the exhaust to appropriate exhaust manipulation equipment. A valve 130, such as a gate valve or the like, may be disposed in the pumping plenum 124 to facilitate controlling the flow rate of the exhaust gas in conjunction with operation of the vacuum pump 128. Although a z-motion gate valve is illustrated, any suitable process compatible valve for controlling the flow of exhaust may be utilized.

In operation, a substrate 110 may enter the processing chamber 100 through an opening 112 in the chamber body 102. The opening 112 may be selectively sealed via a slit valve 118 or other device to selectively provide access to the interior of the chamber through the opening 112. The substrate support 108 may be coupled to a lift device 134, and the lift device 134 may control the position of the substrate support 108 between a lower position suitable for transferring substrates into and out of the chamber via the opening 112 (as shown) and a selectable upper position suitable for processing. The processing locations may be selected to maximize the processing uniformity for a particular processing step. When in the raised processing position, the substrate support 108 may be disposed over the opening 112 to provide a symmetric processing region. After the substrate 110 is disposed within the processing chamber 100, the chamber may be pumped to a pressure suitable for forming a plasma, and one or more process gases may be introduced into the chamber via the showerhead 114 (and/or other gas inlets). RF power may be provided to strike and sustain a plasma from the process gas to process the substrate.

During processing (such as in the above example), the temperature of the showerhead 114 may be controlled to provide a more uniform temperature distribution across the substrate-facing surface of the showerhead 114. The showerhead 114 may include one or more mechanisms for controlling the temperature of the showerhead 114. For example, in some embodiments, one or more fluid passages may be provided within the interior of the showerhead 114 to further facilitate controlling the temperature of the gas distribution plate of the present principles serving as the faceplate 160 of the showerhead 114. In some embodiments, the showerhead 114 may also include a gas distribution plate of the present principles as an optional blocker plate 161, and the blocker plate 161 may also include one or more fluid passages to facilitate controlling the temperature of the blocker plate.

In addition, a first set of one or more channels 140 may be provided in the face plate 160 of the showerhead 114 to define one or more flow paths (described more fully below) for the heat transfer medium to flow through the one or more channels 140. A second set of one or more channels 162 may optionally be provided in an optional baffle plate 161 of the showerhead 114 to define one or more flow paths (described more fully below) for the heat transfer medium to flow through the optional baffle plate 161. The heat transfer medium may include any fluid suitable to provide sufficient thermal conduction to or from the components (e.g., baffle plate, faceplate, etc.) of the showerhead 114. By way of example, the heat transfer medium may be a gas (such as helium (He), oxygen (O2), or the like) or a liquid (such as water, antifreeze, or an alcohol (e.g., glycerol, ethylene glycerol, propylene, methanol, or refrigerant fluid (such as,

(e.g., chlorofluorocarbon or hydrochlorofluorocarbon refrigerants)), ammonia, or the like)). The optional barrier plate 161 and the face plate 160 may have different heat transfer media and/or different heat transfer parameters (such as, for example, flow rate).

A heat transfer medium source 136 may be coupled to the channels 140, 162 to provide heat transfer medium to one or more of the channels 140, 162. The heat transfer medium source 136 may include a temperature control device (e.g., a cooler or heater) to control the temperature of the heat transfer medium. One or more valves 139 (or other flow control devices) may be provided between the heat transfer medium source 136 and the one or more channels 140, 162 to independently control the rate of flow of the heat transfer medium to the one or more channels 140, 162. The controller 137 may control the operation of one or more valves 139 and/or the heat transfer medium source 136.

In some embodiments, one or more heat sinks (not shown) may be embedded in the showerhead 114 (including, for example, in the faceplate 160 or optional baffle 161). The heat sink helps stabilize the temperature of the panel 160 or optional barrier plate 161. The heat sink may be made of a different material than the material used to make the showerhead 114 (including the faceplate or baffle). In some embodiments, the heat spreader is at least partially made of a copper-based material.

The following examples illustrate embodiments in which the gas distribution plate is used as a faceplate in a showerhead of a semiconductor processing apparatus. However, other embodiments use the gas distribution plate as a baffle plate inside a showerhead of a semiconductor processing apparatus. In both types of embodiments, the formation of the gas passages and heat transfer passages is similar, and therefore, for the sake of brevity, the gas distribution plate is illustrated as an example of a panel. However, the techniques of the present principles may also be used to form baffle plates and other types of gas distribution plates.

Fig. 2 illustrates a schematic cross-sectional view of an apparatus 200 for gas delivery according to some embodiments of the present principles. The apparatus 200 (e.g., a "showerhead") has a flange 202 that engages a gas distribution plate 204. In some embodiments, the flange 202 has a substantially uniform thickness. The device 200 may comprise two separate pieces that are joined in a temporary (e.g., screws, clamps, etc.) or permanent manner (e.g., cold welding, etc.). The apparatus 200 may also comprise a single piece including the flange 202 and the gas distribution plate 204. The gas distribution plate 204 includes at least one gas passage 206 or "hole" having an inner surface. As the fluid passes through the passage, the fluid (e.g., gas, liquid, etc.) is affected by the passage.

The effects may include affecting (e.g., decreasing, increasing) fluid velocity, fluid density (e.g., expanding, compressing), and fluid temperature (e.g., increasing, decreasing). The passages may also affect laminar flow of the fluid. If the inner surface of the passageway is rough, the laminar flow will be disrupted, resulting in turbulent fluid delivery into the processing chamber 100. The turbulence may cause uneven gas delivery with negative impact on substrate processing within the processing chamber 100. Turbulence affects fluid parameters (such as density, velocity, and temperature). In some embodiments, an apparatus for gas delivery with reduced via surface roughness advantageously provides uniformity of parameters (such as fluid density, velocity, and temperature) while increasing the quality of substrate processing. An average surface roughness (Ra) of the inner surfaces of the gas distribution plate passages of less than or equal to about 10Ra can be achieved. An average surface roughness (Ra) of the inner surfaces of the gas distribution plate passages of less than or equal to about 2Ra can be achieved, such as by utilizing materials (e.g., glass and other materials). Furthermore, the inventors have also found that the process of the present principles advantageously provides a smoother transition between passages having varying inner diameters.

The device 200 with improved via surface roughness may be formed in a variety of ways. For simplicity, the following example embodiments utilize a process called electroforming. Electroforming uses electrochemistry and additives in an electroplating bath (plating bath) to produce parts. The metal ions are electrochemically transferred from the anode through the electrolyte to the surface where the metal ions are deposited as atoms. In electroforming, the surface is treated so that metal ions do not adhere. The surface is referred to as a "mandrel". The mandrel acts as a cathode in the electroplating bath. The mandrel may be permanent (as the mandrel may be reused over and over again) or the mandrel may be disposable (as the mandrel may be broken to release the electroformed part after the part is formed). In some embodiments, the gas distribution plate 204 is made of at least two different materials (such as, for example, nickel and copper).

Fig. 3 illustrates a schematic cross-sectional view of a mandrel 300 having a non-conductive and permanent pin 304 according to some embodiments of the present principles. Mandrel 300 is an example of a form or jig (jigs) that may be used in an electroforming process to produce, for example, apparatus 200 of fig. 2. In some embodiments, mandrel 300 has a base 302, base 302 has pins 304, pins 304 are made of a non-conductive material (do not attract metal ions during electroforming), and can be reused (permanent). For example, the pin 304 may be formed from a material such as glass, plastic, including nylon and extruded nylon (e.g., fishing line), and the like. For example, the pins 304 may be nylon fishing lines having different diameters to thread through holes in the base 302 of the mandrel 300 and to be looped through or attached to an overhead weaving device (aerial apparatus) to act as "pins" during the electroforming process. The pin or fishing line is generally oriented at a right angle to the base 302, but in some embodiments other angles may be used to provide different gas delivery angles for the gas delivery device. Glass rods may also be used as the material for the pins 304 due to the low surface roughness of the glass. An average surface roughness or Ra of less than or equal to 2 can be achieved.

The electroforming process is used to form the gas distribution plate 204, with the gas distribution plate 204 being substantially uniform over the base 302 and around the pins 304. Because the pins 304 are non-conductive, the material used for the electroforming process is not attracted to the pins 304. The lack of attraction allows material to accumulate on the base 302 at a somewhat uniform thickness to form the gas distribution plate 204. The pins 304 may also be easily separated from the gas distribution plate, and the pins 304 are "permanent" in the sense that the pins 304 do not need to be sacrificed to remove the gas distribution plate 204 from the mandrel 300 and may be reused to manufacture additional gas distribution plates. The gas distribution plate may be removed from the mandrel 300 and used, or the gas distribution plate may be further processed (such as to machine the surface and/or ensure uniform thickness). The gas distribution plate may also be machined to appropriately engage the flange 202 and/or may be cold-welded to the flange 202.

Fig. 4a illustrates a schematic cross-sectional view of a mandrel 400a having a non-conductive and permanent pin 304 and tubes 404a, 404b, 404c according to some embodiments of the present principles. The mandrel 400a includes the base 302 and the pin 304 of fig. 3. The electroforming process has deposited a first layer of material 402 onto the mandrel 400 a. The pins 304 create vias in the first material layer 402 having a first diameter 405. Before continuing the electroforming process, the first material layer 402 may be removed or left in place before continuing and the first material layer 402 processed or otherwise treated. Additional processing may include, but is not limited to, machining the top surface of the first material layer 402 to achieve a uniform thickness of the first material layer 402. After processing, the first material layer 402 may be returned to the mandrel 400a for additional electroforming.

The tube 404a has a cylindrical opening in the center of the tube 404a that is slightly larger than the first diameter 405 of the pin 304. The openings allow the tube 404a to slide over the pin 304 and engage the first material layer 402. Once the tube 404a is placed over the pin 304, the mandrel 400a can now be used to form a gas passage having a diameter equal to the second diameter 407, the second diameter 407 being the outer diameter of the tube 404 a. The optional tubes 404b, 404c are examples of other shapes that may be used to allow easy removal from the formed gas distribution plate (reusable or "permanent"). The optional shape of the tubes 404b, 404c allows for a smoother transition from the first diameter 405 to the second diameter 407 within the passages of the gas distribution plate. Other shapes (e.g., square, oval, hour-glass, etc.) may be used instead of the illustrated example.

Fig. 4b illustrates a schematic cross-sectional view of a mandrel 400b having a non-conductive and permanent pin 304 and having a tubular 404a after forming an apparatus for gas delivery according to some embodiments of the present principles. For illustrative purposes only, the mandrel 400b uses the tube 404a ( alternative tubes 404b, 404c and/or combinations of tube variations shown and not shown may also be used). The electroforming process has deposited a second material layer 406 over the first material layer 402. Once the mandrel 400b is removed, the combined first material layer 402 and second material layer 406 form a gas distribution plate. The gas distribution plate in the example will have two different diameter gas passages. The varying diameter can be used to vary the gas pressure, temperature, and velocity of the delivered gas. The gas distribution plate may be removed from the mandrel 400b and used, or the gas distribution plate may be further processed (such as to machine the surface and/or ensure a uniform thickness). The gas distribution plate may also be machined to appropriately engage the flange 202 and/or may be cold-welded to the flange 202 as a faceplate. The gas distribution plate may also be integrated as a baffle plate.

Fig. 5 illustrates a schematic cross-sectional view of a mandrel 500 having a pin 504 that is non-conductive and disposable, according to some embodiments of the present principles. In some embodiments, the mandrel 500 has a base 502, the base 502 having a pin 504. Because the pins 504 are non-conductive, the electroforming process distributes a somewhat uniform layer of material 506 onto the mandrel 500. Due to the shape of the pins 504, the pins 504 cannot be easily removed from the material layer 506, so the pins 504 are made disposable. The pins 504 will be sacrificial after the electroforming process. Removal of the pins 504 may be accomplished by heating (e.g., wax-based pins), by etching (e.g., using an etchant that etches only the material used for the pins 504), and other chemical or mechanical means.

The gas distribution plate can be removed from the mandrel 500 and used, or the gas distribution plate can be further processed (such as to machine the surface and/or ensure uniform thickness). The gas distribution plate may also be machined to appropriately engage the flange 202 and/or may be cold-welded to the flange 202.

Fig. 6 illustrates a schematic cross-sectional view of a mandrel 600 having a pin 604 made of an electrically conductive material according to some embodiments of the present principles. The mandrel 600 has a base 602, the base 602 having pins 604, the pins 604 will attract metal ions in the electroforming process. Although the diameter of the pin 604 is uniform in the illustration, the diameter may be non-uniform (curved, angled, hourglass, etc.). In some embodiments, the first material layer 606 is deposited using an electroforming process. Since the pin 604 attracts metal ions, the pin 604 and the base 602 are coated with a layer of metal. The process forms a rough hollow cone 605 around the pin 604. In some electroforming processes, one or more cavities 610 surrounding rough hollow cones 605 may be filled with a substance, such as, for example, wax or other substance that may be removed from the formed pieces. By selectively filling the cavity 610, various configurations of fluid pathways may be achieved to allow temperature control of the gas distribution plate. For example, forming the fluid passages near the outer edge of the gas distribution plate can control the edge temperature of the gas distribution plate. For example, similarly, forming the fluid passage near the center of the gas distribution plate can control the center temperature of the gas distribution plate.

Before continuing the electroforming process, the first material layer 606 may be removed or left in place and machined or otherwise processed before continuing. Additional processing may include, but is not limited to, machining the top surface of the first material layer 606 to achieve a uniform thickness of the first material layer 606. After processing, the first material layer 606 may be returned to the mandrel 600 for additional electroforming.

A second material layer 608 is then electroformed over the species and the first material layer 606. A metal coating may be used on the substance in the cavity to attract metal ions to form a substantially uniform layer. For example, the metal coating may be sprayed on the substance prior to electroforming. In some embodiments, the second material layer 608 may be processed to remove any thickness non-uniformities that may be caused by the attraction of metal ions to the pins 604 during the formation of the second material layer 608. In some embodiments, the portion 607 of the pin 604 that extends beyond the top surface of the first material layer 606 may be made of a non-conductive material to aid in the uniformity of the second layer and may require further processing.

The gas distribution plate may be removed from the mandrel 600 and used, or the gas distribution plate may be further processed (e.g., to machine the surface and/or to ensure uniform thickness). The gas distribution plate may also be machined to appropriately engage the flange 202 and/or may be cold-welded to the flange 202 as a faceplate. A gas distribution plate may also be used as the baffle plate.

In some embodiments, cavity 612 may be constructed using similar processes as described above along the perimeter of the apparatus for gas delivery. The inner pins may be non-conductive to create a uniform layer of the first material, while the outer conductive member may be used to create a flow channel along the perimeter. Strategic use of conductive and non-conductive components may be used to selectively create cavities in the gas distribution plate. In some embodiments, a cavity formed around the via during the electroforming process may be filled with a heat sink material. The process allows the heat sink to be embedded throughout the gas distribution plate (e.g., around one or more passages) or in selective locations, helping to achieve uniform temperature control of the gas distribution plate. The heat spreader material may remain exposed (e.g., no second material layer 608 formed) or partially embedded (e.g., second material layer 608 formed). In some embodiments, a combination of heat sinks and fluid passages in the gas distribution plate can be created to control the temperature of the gas distribution plate.

Fig. 7 is a flow chart illustrating a method 700 of forming an apparatus for gas delivery according to an embodiment of the present principles. The method begins by providing a mandrel having a conductive base to form a gas distribution plate (702). The electrically conductive base generally helps to form one surface of the gas distribution plate and the general shape of the gas distribution plate. The mandrel may also include fastening means to secure pins used to form the passages in the gas distribution plate. For example, the fastening means may include holes for threading the string (e.g., fishing line or nylon line used as a pin to form a passage), recesses for the pin (e.g., friction retention of a glass rod, plastic pins, etc.), and/or screws or other permanent or semi-permanent fastening means. Then, a passage shape of the gas distribution plate is determined (704). The shapes may include, but are not limited to, a cylinder, an hourglass (narrowed center), a cylinder with a stepped diameter, a cylinder with a gradually decreasing diameter, and/or a cylinder with an abrupt change in diameter. The shape is not limited to a cylindrical shape. Implementations utilizing principles of the present disclosure may also implement square, triangular, oval, and/or other shaped passageways. The pin is then engaged with the mandrel according to the shape of the passage (706). In some embodiments, the pins may have multiple parts (e.g., pins and tubes, etc.) and may be conductive or non-conductive, or a combination of conductive and non-conductive portions, and may be permanent or disposable to create the passages in the gas distribution plate.

Then, electroforming is performed on the mandrel (708). The electroforming process may include multiple electroforming processes to form multiple layers of similar or different materials, or to form cavities within the gas distribution plate, or to embed heat sinks in the gas distribution plate. Additional processing or other treatment may be performed between one or more of the layers. The gas distribution plate is then released from the mandrel (710). After release, further processing may be performed, or the gas distribution plate may be used without processing. The disposable portion of the pin or tube may be etched away or otherwise removed. Wax or other removable substances used during processing may also be removed from the inner and/or outer cavities and the like.

Each block of method 700 need not be performed, and some blocks may be performed out of order. Some blocks may also be repeated.

While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof.