High density vertically segmented silicon coatings for low defectivity in high temperature rapid thermal processing.

Abstract

The present application generally relates to a chamber component for a thermal processing chamber comprising a base component having a coating disposed thereon, the coating comprising a surface, a thickness, and a plurality of cracks extending from the surface of the coating through at least 40 percent of the thickness of the coating.

Description

[Technical field]

[0001] The present disclosure relates generally to parts used in processing substrates, such as in semiconductor processing applications, and methods for forming coatings thereon. In particular, the present invention relates to air plasma sprayed silicon coatings formed on processing chamber parts to prevent the growth and formation of hairline fractures, and methods for forming the coatings. [Background technology]

[0002] Plasma spraying is a coating process in which a powder of coating material is fed into a plasma jet. A plasma spray torch creates a plasma in a rapidly flowing gas stream. The plasma melts the powder and sprays the coating material onto a target. Upon impact, the molten particles cool and instantly solidify, coating the target material.

[0003] Many components of processing chambers are coated for protection in high temperature processing environments. However, coating materials applied by typical atmospheric plasma spray (APS) silicon coatings cannot experience large thermal gradients without suffering coating damage. Because APS silicon coatings have low in-plane compliance, they are prone to cracking when used at high temperatures under large thermal transient stresses. Thermal stress relaxation and thermal contraction of silicon coatings cause existing hairline cracks to grow and new cracks to form in the coating during rapid thermal processing (RTP). The growth of existing cracks and the formation of new cracks release particles from the coated components into the processing space of processing chambers, such as RTP chambers, which causes defects on substrates being processed in the chamber. Moreover, as silicon coatings are exposed to repeated thermal cycles over time during substrate processing, existing cracks continue to grow and new cracks continue to form, resulting in a never-ending cycle of new particles being released into the processing space of the processing chamber.

[0004] Furthermore, simply polishing the coating to remove new particles does not solve the problem, as new cracks continue to form even when the previous coating layer is polished away.Therefore, there is a need to form a silicon APS coating for parts used in processing chambers that reduces the likelihood of particle defects on the substrate being processed when used in high temperature and thermally transient applications. Summary of the Invention

[0005] In one embodiment, a chamber component for a thermal processing chamber is provided. The chamber component includes a base component having a coating disposed thereon. The coating includes a surface, a thickness, and a plurality of cracks extending from the surface of the coating through at least 40 percent of the thickness of the coating.

[0006] In another embodiment, a support ring for use in a heat treatment chamber is provided having a coating disposed thereon, the coating including a surface, a thickness, and a plurality of cracks extending from the surface of the coating through at least 40 percent of the thickness of the coating, the average spacing between the plurality of cracks being between 70 μm and 125 μm.

[0007] In yet another embodiment, a thermal treatment chamber is provided. The thermal treatment chamber includes a chamber body including a base, one or more sidewalls, and a lid that enclose a processing space. The thermal treatment chamber further includes a substrate support disposed within the processing space, the substrate support including a support cylinder, a support ring, and an edge ring. The support ring has a coating disposed thereon. The coating includes a surface, a thickness, and a plurality of cracks extending from the surface of the coating through at least 40 percent of the thickness of the coating.

[0008] So that the above recited features of the present disclosure may be understood in detail, a more particular description of the present disclosure, briefly summarized above, may be made by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that since the present disclosure may admit of other equally effective embodiments, the accompanying drawings merely illustrate typical embodiments of the present disclosure and therefore should not be considered as limiting its scope. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 illustrates a simplified isometric view of a process chamber, according to one embodiment. [Diagram 2] FIG. 1 illustrates a cross-sectional view of a support ring with an air plasma sprayed (APS) silicon coating according to one embodiment. [Diagram 3] FIG. 2 is a cross-sectional view of an APS silicone coating, according to one embodiment. [Figure 4] FIG. 1 is a chart comparing various crack depths in an APS silicone coating, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] In the following description, numerous specific details are set forth to provide a more thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described to avoid obscuring the invention.

[0011] As typical air plasma spray (APS) silicon coatings formed on substrate processing chamber parts, such as rapid thermal processing (RTP) chamber parts, are subjected to repeated thermal cycles, the silicon coating begins to crack, releasing tensile stresses across the coating. Growth of existing cracks and formation of new cracks in the APS silicon coating releases particles that cause particle defects on the substrate during processing. The cracks generally initiate at hotter locations within the RTP chamber. The cracks initiate and propagate along the coated part. As the coated part is subjected to additional thermal cycles, the existing cracks continue to grow and new cracks continue to form, resulting in a never-ending cycle of new particles being released into the processing space of the RTP chamber.

[0012] To solve the problems described above, the present disclosure provides an APS silicon coating that can be formed on chamber components having large, pre-existing cracks formed through the thickness of the APS silicon coating to reduce thermal strain during processing. The inventors have discovered that by forming an APS coating with a pre-cracked configuration on a chamber component, new cracks are prevented from forming in the coating during typical thermal operation of processing substrates, such as in an RTP chamber.

[0013] 1 is a simplified isometric view of one embodiment of a rapid thermal processing system 100. The rapid thermal processing system 100 includes a processing chamber 101, a stator assembly 118, an atmospheric control system 164, and a controller 124. The processing chamber 101 includes a chamber body 102 with walls 108, a bottom 110, and a top 112. The walls 108, the bottom 110, and the top 112 define an interior volume 120. The walls 108 generally include at least one substrate access port 148 to facilitate entry and exit of a substrate 140 (a portion of which is shown in FIG. 1). In some configurations, the access port may be coupled to a transfer chamber (not shown) or a load lock chamber (not shown) and selectively sealed with a valve.

[0014] Examples of rapid thermal processing chambers that may be adapted to benefit from the present disclosure are the Centura RadOx, Radiance, RadOx 2, and Vulcan thermal processing systems. These rapid thermal processing chambers are available from Applied Materials, Inc., located in Santa Clara, California. The embodiments described herein may also be utilized in other processing systems and devices where high temperature processing is desired. Examples of other processing systems include substrate support platforms adapted for robotic handoffs, orientation devices, deposition chambers, etch chambers, electrochemical processing equipment, and chemical mechanical polishing devices, among others, where minimization of particle generation is desired.

[0015] Disposed within the interior volume 120 are a substrate support 104, a window 114, a radiant heat source 106, and a cooling block 180. In some configurations, the radiant heat source 106 is disposed within an inner diameter of the substrate support 104. In one embodiment, the substrate support 104 is magnetically levitated. As shown, the substrate support 104 is annular and includes a support cylinder 154, a support ring 150, and an edge ring 152. The support ring 150 rests on the support cylinder 154, and the edge ring 152 rests on and is nested with the support ring 150. The edge ring 152 has a substrate support surface for receiving a substrate for processing. In one embodiment, the edge ring includes quartz, amorphous silica, or silicon carbide, and may be optionally coated with silicon carbide. In one embodiment, the support ring 150 comprises quartz, bubble quartz, amorphous quartz, or amorphous silica and has a sol coating that blocks the transmission of light from the radiant heat source 106 .

[0016] The window 114 is generally made of a material transparent to heat and various wavelengths of light, such as infrared (IR) light, through which photons from the radiant heat source 106 heat the substrate 140. In one embodiment, the window 114 is made of a quartz material, although other materials transparent to light, such as sapphire, may be used. In one configuration, the window 114 includes a plurality of lift pins 144 coupled to an upper surface of the window 114 adapted to selectively contact and support the substrate 140 to facilitate transfer of the substrate to and from the processing chamber 101. Each of the plurality of lift pins 144 is configured to minimize absorption of energy from the radiant heat source 106 and is made of the same material used for the window 114, such as a quartz material. The plurality of lift pins 144 are positioned and radially spaced apart from one another to facilitate passage of an end effector coupled to a transfer robot (not shown). The end effector and / or robot are capable of horizontal and vertical movement to facilitate transfer of the substrate 140 .

[0017] The radiant heat source 106 includes a lamp assembly formed from a housing including a plurality of honeycomb tubes 160 in a coolant assembly (not shown) coupled to a coolant source 183. The coolant source 183 can be one or a combination of water, ethylene glycol, nitrogen (N2), and helium (He). The housing can be made from a copper material or other suitable material, with suitable coolant channels formed therein for the flow of coolant from the coolant source 183. Each honeycomb tube 160 can include a reflector and a high intensity lamp assembly or an IR emitter. The radiant heat source 106 can further include an annular zone, and the voltage supplied by the controller 124 to the plurality of honeycomb tubes 160 can be varied to improve the radial distribution of energy from the honeycomb tubes 160. Dynamic control of the heating of the substrate 140 can be performed by one or more temperature sensors 117 adapted to measure the temperature across the substrate 140.

[0018] The stator assembly 118 circumscribes the wall 108 of the chamber body 102 and is coupled to one or more actuator assemblies 122 that control the elevation of the stator assembly 118 along the exterior of the chamber body 102. The stator assembly 118 is magnetically coupled to a substrate support 104 disposed within the interior volume 120 of the chamber body 102. The substrate support 104 includes a magnetic portion for functioning as a rotor, which may thus provide a magnetic bearing assembly for lifting and / or rotating the substrate support 104. In one embodiment, at least a portion of the substrate support 104 is partially surrounded by a trough (not shown) coupled to a fluid source 186 that may include water, ethylene glycol, nitrogen (N2), helium (He), or a combination thereof adapted as a heat exchange medium for the substrate support. The stator assembly 118 may also include a housing 190 for enclosing various portions and components of the stator assembly 118. In one embodiment, the stator assembly 118 includes a drive coil assembly 168 stacked on a suspended coil assembly 170. The drive coil assembly 168 may be adapted to rotate and / or raise / lower the substrate support 104, and the suspended coil assembly 170 may be adapted to passively center the substrate support 104 within the processing chamber 101. Alternatively, the rotation and centering functions may be performed by a stator having a single coil assembly.

[0019] An atmospheric control system 164 is also coupled to the interior volume 120 of the chamber body 102. The atmospheric control system 164 generally includes a throttle valve and a vacuum pump for controlling the chamber pressure. The atmospheric control system 164 may also be adapted to deliver process gases for the thermal deposition process.

[0020] The processing chamber 101 also includes a controller 124, which generally includes a central processing unit (CPU) 130, support circuits 128, and memory 126. The CPU 130 may be one of any form of computer processor that may be used in an industrial setting to control various actions and sub-processors. The memory 126, or computer readable medium, may be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, or any other form of local or remote digital storage, and is generally coupled to the CPU 130. The support circuits 128 are coupled to the CPU 130 for supporting the controller 124 in a conventional manner. These circuits include cache, power supplies, clock circuits, input / output circuits, subsystems, and the like.

[0021] In one embodiment, each of the actuator assemblies 122 generally comprises a precision lead screw 132 coupled between two flanges 134 extending from the wall 108 of the chamber body 102. The lead screw 132 has a nut 158 ​​that advances axially along its threads as the lead screw 132 rotates. A coupling 136 is coupled between the stator assembly 118 and the nut 158 ​​such that the lead screw 132 controls the elevation of the stator assembly 118 at its interface with the coupling 136. Thus, as the lead screw 132 of one of the actuator assemblies 122 is rotated causing a relative displacement between the nuts 158 of the other actuator assembly 122, the horizontal plane of the stator assembly 118 changes with respect to the central axis of the chamber body 102.

[0022] In one embodiment, a motor 138, such as a stepper or servo motor, is coupled to the lead screw 132 to provide controllable rotation in response to signals by the controller 124. Alternatively, other types of actuator assemblies 122 may be utilized to control the linear position of the stator assembly 118, such as pneumatic cylinders, hydraulic cylinders, ball screws, solenoids, linear actuators, and cam followers, among others.

[0023] The processing chamber 101 also includes one or more sensors 116, which are generally adapted to detect an elevation of the substrate support 104 (or substrate 140) within the interior volume 120 of the chamber body 102. The sensor 116 may be coupled to the chamber body 102 and / or other portions of the processing chamber 101 and may be adapted to provide an output indicative of the distance between the substrate support 104 and the top 112 and / or bottom 110 of the chamber body 102, and may also detect misalignment of the substrate support 104 and / or substrate 140.

[0024] The one or more sensors 116 are coupled to a controller 124, which receives output metrics from the sensors 116 and provides one or more signals to one or more actuator assemblies 122 to raise or lower at least a portion of the substrate support 104. The controller 124 may utilize the position metrics obtained from the sensors 116 to adjust the elevation of the stator assembly 118 in each actuator assembly 122 such that both the elevation and planarity of the substrate support 104 and the substrate 140 mounted thereon may be adjusted relative to a central axis of the processing chamber 101 (e.g., a rapid thermal processing (RTP) chamber) and / or the radiant heat source 106. For example, the controller 124 may provide a signal to raise the substrate support by action of one actuator assembly 122 to correct for axial misalignment of the substrate support 104, or the controller may provide a signal to all actuator assemblies 122 to facilitate simultaneous vertical movement of the substrate support 104.

[0025] The one or more sensors 116 may be ultrasonic, laser-inductive, capacitive, or other types of sensors capable of detecting the proximity of the substrate support 104 within the chamber body 102. The sensor 116 may be coupled to the chamber body 102 proximate the top 112 or coupled to the wall 108, although other locations within and around the chamber body 102 may be suitable, such as coupled to a stator assembly 118 outside the processing chamber 101. In one embodiment, the one or more sensors 116 may be coupled to the stator assembly 118 and adapted to sense the elevation and / or position of the substrate support 104 (or substrate 140) through the wall 108. In this embodiment, the wall 108 may include a thinner cross-section to facilitate position sensing through the wall 108.

[0026] The processing chamber 101 also includes one or more temperature sensors 117 that may be adapted to sense the temperature of the substrate 140 before, during, and after processing. In the embodiment shown in FIG. 1, the temperature sensor 117 is disposed through the top 112, although other locations in and around the chamber body 102 may be used. The temperature sensor 117 may be an optical pyrometer, as an example, a pyrometer having a fiber optic probe. The temperature sensor 117 may be adapted to be coupled to the top 112 in a configuration for sensing the entire diameter of the substrate, or a portion of the substrate. The temperature sensor 117 may comprise a pattern that defines a sensing area substantially equal to the diameter of the substrate, or a sensing area substantially equal to the diameter of the substrate, or a sensing area substantially equal to one radial to the substrate. For example, multiple temperature sensors 117 may be coupled to the top 112 in a radial or linear configuration to enable a sensing area spanning the radius or diameter of the substrate. In one embodiment (not shown), multiple temperature sensors 117 may be arranged in a line extending radially from the center of the top 112 to a peripheral portion of the top 112. In this manner, the radius of the substrate can be monitored by the temperature sensor 117, which allows for sensing the diameter of the substrate as it rotates.

[0027] The processing chamber 101 (e.g., an RTP chamber) also includes a cooling block 180 adjacent to, coupled to, or formed in the top portion 112. Generally, the cooling block 180 is spaced apart and opposite the radiant heat source 106. The cooling block 180 includes one or more coolant channels 184 coupled to an inlet 181A and an outlet 181B. The cooling block 180 includes one or more coolant channels 184 coupled to an inlet 181A and an outlet 181B. The cooling block 180 may be made from a process-resistant material, such as stainless steel, aluminum, a polymer, or a ceramic material. The coolant channels 184 may include a spiral pattern, a rectangular pattern, a circular pattern, or combinations thereof, and the coolant channels 184 may be integrally formed in the cooling block 180, for example, by casting the cooling block 180 and / or by making the cooling block 180 from two or more pieces and joining the pieces. Additionally or alternatively, coolant channels 184 may be drilled into the cooling block 180 .

[0028] As described herein, the processing chamber 101 is adapted to receive a substrate in a "face-up" orientation, with the deposition-receiving side or face of the substrate oriented toward the cooling block 180 and the "backside" of the substrate facing toward the radiant heat source 106. The "face-up" orientation may allow energy from the radiant heat source 106 to be absorbed more rapidly by the substrate because the backside of the substrate 140 is generally less reflective than the front side of the substrate.

[0029] Although the cooling block 180 and the radiant heat source 106 are described as being disposed in the upper and lower portions of the interior volume 120, respectively, the positions of the cooling block 180 and the radiant heat source 106 may be reversed. For example, the cooling block 180 may be sized and configured to be disposed within an inner diameter of the substrate support 104, and the radiant heat source 106 may be coupled to the upper portion 112. In this configuration, the window 114 may be disposed between the radiant heat sources 106 in the upper portion of the processing chamber 101. In one configuration, the window 114 is made from quartz. The substrate 140 may absorb heat more easily when the backside faces the radiant heat source 106, but the substrate 140 may be oriented in either a face-up or face-down orientation.

[0030] The inlet 181A and outlet 181B may be coupled by valves and suitable piping to a coolant source 183. The coolant source 183 is in communication with the controller 124 to facilitate control of the pressure and / or flow of a fluid disposed therein. The fluid may be water, ethylene glycol, nitrogen (N2), helium (He), or other fluids used as a heat exchange medium.

[0031] FIG. 2 is a cross-sectional view of a support ring 150, according to one embodiment. As seen in FIG. 2, the support ring 150 is generally annular in shape and includes an inner radius 202, an outer radius 204, a first side 206, and a second side 208. The support ring 150 further includes a first protrusion 210 and a second protrusion 212. The support ring 150 is an example of a portion that is generally covered in a silicon coating 250. It should be noted that although the coating 250 is referred to herein as a "silicon coating," the coating 250 can be any coating that is primarily silicon. For example, the silicon coating 250 can include silicon oxide (SiO2) since some oxidation of silicon can generally occur during the formation of the silicon coating 250.

[0032] The inner radius 202 has a first protrusion 210 extending outwardly from a plane defined by the first side 206. The first protrusion 210 is used to engage a complimentary projection on a second support member (e.g., the edge ring at 152 in FIG. 1). The engaged protrusion is useful for securely locating the second support member with the first support member.

[0033] The first protrusion 210 protrudes from the first side 206 any distance necessary to keep the second support member securely in place. In one configuration, the protrusion extends outwardly from the first side between 0.01 inches and 0.1 inches (e.g., 0.04 inches). However, the length of the first protrusion 210 may also be dictated by spacing constraints that may exist in alternative embodiments.

[0034] In some embodiments, the outer radius 204 includes a second protrusion 212 extending outwardly from the second side 208. The second protrusion 212 is used to engage a third support member (e.g., the support cylinder of FIG. 1). The second protrusion 212 can engage the third support member by extending along an outer surface of the third support member or by extending along an inner surface of the third support member. In some configurations, the second protrusion 212 can engage the third support member by extending beyond the radius of the third support member such that the support ring 150 rests on the third support member. In another configuration, the radius of the second protrusion 212 is the same as the outer radius 204.

[0035] The support ring 150 is coated with a silicon coating 250. The silicon coating 250 is a microstructured, pre-cracked silicon coating that improves the in-plane strain compliance of the coating and reduces coating stress. The silicon coating 250 is further described with respect to FIG.

[0036] Figure 3 is a cross-sectional view of a silicone coating 250. Figure 3 includes a support ring 150, one or more pre-treated vertical cracks 310, and one or more hairline cracks 330 in the silicone coating.

[0037] The silicon coating 250 may be applied by atmospheric plasma spraying (APS). The APS process sprays a molten or heat-softened material onto a surface to provide a coating. Typically, the material in the form of a powder is injected into a high-temperature plasma flame, where it is rapidly heated and accelerated to a high velocity. The hot material impinges on the surface of the substrate and cools rapidly to form a coating. Upon impacting the surface of the part, each molten droplet forms a pancake-like structure that rapidly solidifies. The pancake-like structures overlap one another so that the deposit builds up to a desired thickness. Typically, the APS process is performed at atmospheric pressure. Plasma spraying has the advantage that it can spray materials with extremely high melting points, such as silicon. Additionally, plasma spray coatings are generally much denser, stronger, and cleaner than other thermal spray processes. Although APS is referred to herein, it should be noted that the silicon coating 250 may be applied by low pressure plasma spraying, vacuum plasma spraying (VPS), or inert-shrouded APS. These spraying techniques are similar to APS, except that they are performed at low pressure or in an inert environment to minimize oxidation of the silicon coating 250.

[0038] Although the silicon coating shown in Figure 3 has some hairline cracks 330 that may be caused by freeze-quenching stresses from splat solidification or by thermal expansion mismatch of the stresses of repeated thermal cycles in the processing chamber 101, the hairline cracks 330 do not relieve stress in the coating 250. As can be seen in Figure 3, the hairline cracks 330 do not penetrate deeply into the coating 250. Thus, the shallowness of the hairline cracks 330 does not relieve stress in their current state and in some cases may only result in more grains as new hairline cracks form or existing hairline cracks grow during repeated heating and cooling in the processing chamber 101.

[0039] As seen in FIG. 3, the silicon coating 250 includes large, deep, vertical cracks 310 in the coating 250, which may be formed during the formation of the coating 250 or during a post-treatment process. In one embodiment, the large, deep vertical cracks are present in the as-sprayed silicon to produce the coating 250 by controlling the plasma spray conditions, such as molten particle temperature, particle velocity, torch spray distance, powder feed rate, deposition rate, substrate temperature, and substrate rotation. In another embodiment, the cracks 330 are produced after the silicon coating 250 is applied. The presence of the deep vertical cracks 310 in the dense silicon coating 250 provides a coating with higher in-plane elastic compliance, or equivalently, lower in-plane stiffness. The higher in-plane compliance allows for lower coating stresses due to temperature transients, temperature gradients, and thermal expansion mismatch with the substrate 140, allowing the coating to expand and contract upon exposure to heat without the formation of new cracks. Additionally, the higher in-plane compliance allows the coating to expand and contract without introducing new hairline cracks or propagating existing hairline cracks, thus preventing the release of new and additional particles in the RTP process.

[0040] The deep vertical cracks 310 are formed with an average spacing 340 between them. In one embodiment, the average spacing 340 between the deep vertical cracks 310 is between 70 μm and 125 μm, such as between 85 μm and 110 μm.

[0041] In one embodiment, the thickness 350 of the silicon coating 250 is between 10 μm and 150 μm. In one example, the deep crack 310 extends through at least 40 percent of the thickness 350 of the coating 250. For example, the deep crack 310 extends between 40 percent and 100 percent of the thickness 350 of the coating 250. In one embodiment, the deep crack 310 extends between 60 percent and 100 percent of the thickness 350 of the coating 250.

[0042] 4 is a scanning electron microscope (SEM) image of a coating 400, such as silicon coating 250, having multiple deep cracks 401-408. 2 In one embodiment, the coating 400 contains between 8 and 20 deep cracks per surface area. 2 The coating 400 includes between 14 and 20 deep cracks per surface area. Each of the deep cracks 401-408 has an individual crack length. In one embodiment, each crack length ranges from 1 μm to 200 μm. The total length of the deep cracks 401-408 contained within the coating 400 is an important indication of strain compliance. In one embodiment, the total length of the deep cracks 401-408 ranges from 1 μm to 200 μm. 2 In another embodiment, the total length of the deep cracks 401-408 is within 1 μm of the coating 400. 2 In yet another embodiment, the total length of the deep cracks 401-408 is within 1 μm of the coating 400. 2 Contains 14nm to 20nm per surface area.

[0043] While the forgoing is directed to embodiments of the present disclosure, other and future embodiments of the present disclosure may be devised without departing from the basic scope thereof, which scope is determined by the following claims.

Claims

1. 1. A chamber component for a thermal processing chamber, comprising: a base component having a coating disposed thereon, the coating comprising: Surface and Thickness and a plurality of cracks extending from the surface of the coating through at least 40 percent of the thickness of the coating; 2. A chamber part comprising:

2. The chamber component of claim 1 , wherein the plurality of cracks propagate between 60 and 100 percent of the thickness of the coating.

3. The plurality of cracks are each 100 μm ２ 3. The chamber component of claim 2, comprising between 8 and 20 cracks per square inch.

4. The chamber component of claim 3 , wherein the plurality of cracks each have a length between 1 μm and 200 μm.

5. The total average length of the plurality of cracks is 1 μm ２ The chamber component of claim 2 , wherein the thickness of the first and second electrodes is between 8 nm and 14 nm per second.

6. The chamber component of claim 2 , wherein an average spacing between the plurality of cracks is between 70 μm and 125 μm.

7. The chamber component of claim 1 , wherein the coating is one of an air plasma sprayed silicon coating, a low pressure plasma sprayed silicon coating, or a vacuum plasma sprayed silicon coating.

8. 1. A support ring for use in a thermal processing chamber, the support ring having a coating disposed thereon, the coating comprising: Surface and Thickness and a plurality of cracks extending from the surface of the coating through at least 40 percent of the thickness of the coating, the average spacing between the plurality of cracks being between 70 μm and 125 μm; a support ring.

9. The plurality of cracks are each 100 μm ２ 9. The support ring of claim 8, comprising between 8 and 20 cracks per ring.

10. The support ring of claim 8 , wherein the plurality of cracks each have a length between 1 μm and 200 μm.

11. The total average length of the plurality of cracks is 1 μm ２ 11. The support ring of claim 10, wherein the surface roughness is between 8 nm and 14 nm per square inch.

12. The plurality of cracks are each 100 μm ２ 11. The support ring of claim 10, comprising between 12 and 18 cracks per ring.

13. a chamber body including a base, one or more sidewalls, and a lid that encloses a processing space; a substrate support disposed within the processing space, the substrate support comprising a support cylinder, a support ring, and an edge ring, the support ring having a coating disposed thereon, the coating comprising: Surface and Thickness and a plurality of cracks extending from the surface of the coating through at least 40 percent of the thickness of the coating; a substrate support comprising: A thermal treatment chamber comprising:

14. The thermal treatment chamber of claim 13 , wherein the plurality of cracks propagate between 60 and 100 percent of the thickness of the coating.

15. The plurality of cracks are each 100 μm ２ 15. The thermal processing chamber of claim 14, comprising between 8 and 20 cracks per unit area.

16. 15. The thermal processing chamber of claim 14, wherein the plurality of cracks each have a length between 1 μm and 200 μm.

17. The total average length of the plurality of cracks is 1 μm ２ 14. The thermal processing chamber of claim 13, wherein the thickness of the thermal processing chamber is between 14 nm and 20 nm per inch.

18. The total average length of the plurality of cracks is 1 μm ２ 14. The thermal processing chamber of claim 13, wherein the surface roughness is between 8 nm and 14 nm per square meter.

19. 14. The thermal processing chamber of claim 13, wherein an average spacing between the plurality of cracks is between 70 μm and 125 μm.

20. 9. The support ring of claim 8, wherein the thickness of the coating is between 10 μm and 150 μm.

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