Pedestal comprising vapor chamber for substrate processing system

Abstract

A substrate support for a substrate processing system includes a susceptor including an upper surface and a lower surface. A vapor chamber is disposed between the susceptor and the substrate, defines a vapor chamber cavity and includes a plurality of capillary structures disposed on a surface within the vapor chamber cavity.

Description

This application is a divisional application of a patent application with application number 201980077518.6, application date November 26, 2019, applicant Lam Research Corporation, and invention-creation name "Chuck with Vapor Chamber for Substrate Processing System". Cross - Reference to Related Applications

[0001] This application claims the benefit of U.S. Provisional Application No. 62 / 772,364, filed on November 28, 2018. The entire disclosure of the above - cited application is incorporated herein by reference. Technical Field

[0002] The present disclosure relates to substrate processing systems, and more particularly to a pedestal temperature control system for a substrate processing system. Background Art

[0003] The background description provided here is for the purpose of generally presenting the background of the present disclosure. The work of the currently named inventors, to the extent it is described in this background art section and in various aspects of the specification that could not be determined to be prior art at the time of filing the application, is neither expressly nor implicitly admitted to be prior art against the present disclosure.

[0004] Substrate processing systems typically include a processing chamber having a pedestal. A substrate, such as a semiconductor wafer, can be disposed on the pedestal. For example, in a chemical vapor deposition (CVD) process, a gas mixture can be introduced into the processing chamber to deposit a film on the substrate or etch the substrate. In some cases, a plasma can be used. It is desirable to control the temperature of the pedestal and the substrate during processing to improve the uniformity of etching or deposition.

[0005] To improve temperature uniformity, some systems use multiple heaters embedded in different heating zones of the pedestal. For example, heaters can be arranged at different radii of the pedestal. Thermocouples can be used to monitor the temperature of the heating zones. A control system controls the power supplied to each heating zone to create temperature uniformity based on the temperature measured at different regions of the pedestal. If sensing is not performed in real - time, different types of processes may require different heater calibrations. The control system for the heaters can be expensive and may introduce points of failure into the substrate processing system.

[0006] Despite the use of different heating zones, local temperature differences may still occur. To further improve temperature uniformity, some systems have increased to as many as 30 heaters to achieve a high level of temperature uniformity, thereby increasing cost and complexity. These systems may still not achieve the desired degree of temperature uniformity. Summary of the Invention

[0007] A substrate support for a substrate processing system includes a base that includes an upper surface and a lower surface. A vapor chamber is disposed between the base and the substrate, defining a vapor chamber cavity and including a plurality of capillary structures disposed on a surface within the vapor chamber cavity.

[0008] Among other features, the substrate includes fluid channels that are in thermal communication with a lower surface of the vapor chamber. The fluid channels are arranged in a spiral pattern. A cover is disposed above the fluid channels and adjacent to the lower surface of the vapor chamber. A working fluid is located within the vapor chamber, the plurality of capillary structures are disposed on the lower surface of the vapor chamber, and further includes a fluid supply source configured to supply a fluid having a higher temperature than the working fluid to the fluid channels to cause the working fluid on the plurality of capillary structures to evaporate and condense on a cooler surface of the vapor chamber cavity.

[0009] Among other features, a working fluid is located within the vapor chamber, the plurality of capillary structures are disposed on an upper surface of the vapor chamber, and thermal energy from the base causes the working fluid on the plurality of capillary structures to evaporate and condense on a cooler surface of the vapor chamber cavity. A fluid supply source is configured to supply a fluid having a lower temperature than the working fluid to the fluid channels. The plurality of capillary structures are disposed on at least one of a lower surface, an upper surface, and a sidewall of the vapor chamber cavity.

[0010] Among other features, the vapor chamber performs heating, and the plurality of capillary structures are disposed on a lower surface of the vapor chamber.

[0011] Among other features, the vapor chamber performs cooling, and the plurality of capillary structures are disposed on an upper surface of the vapor chamber. The plurality of capillary structures move the working fluid within the vapor chamber cavity by capillary action. The plurality of capillary structures include a wicking material that moves the working fluid within the vapor chamber cavity by capillary action. The plurality of capillary structures include a fabric that moves the working fluid within the vapor chamber cavity by capillary action. The plurality of capillary structures include a sintered powder material that moves the working fluid within the vapor chamber cavity by capillary action. The plurality of capillary structures include a grooved material that moves the working fluid within the vapor chamber cavity by capillary action.

[0012] A vapor chamber of a substrate support for a substrate processing system includes: a body that includes an upper surface, a lower surface, and a sidewall that define a vapor chamber cavity. A plurality of capillary structures are disposed on at least one of an upper surface, a lower surface, and a sidewall within the vapor chamber cavity. The vapor chamber is configured to be disposed between a base of the substrate support and a substrate.

[0013] Among other features, a working fluid is located within the vapor chamber. The vapor chamber supplies thermal energy to the base. The plurality of capillary structures are disposed on a lower surface of the vapor chamber to cause the working fluid to evaporate and to cause the working fluid to condense on a cooler surface within the vapor chamber cavity.

[0014] Among other features, a working fluid is located within the vapor chamber, the vapor chamber performs cooling of the base, and the plurality of capillary structures are disposed on an upper surface of the vapor chamber to cause the working fluid to evaporate and to cause the working fluid to condense on a cooler surface within the vapor chamber cavity.

[0015] Among other features, the plurality of capillary structures include wicking materials that move the working fluid within the vapor chamber cavity by capillary action. The plurality of capillary structures include fabrics that move the working fluid within the vapor chamber cavity by capillary action. The plurality of capillary structures include sintered powder materials that move the working fluid within the vapor chamber cavity by capillary action. The plurality of capillary structures include grooved materials that move the working fluid within the vapor chamber cavity by capillary action.

[0016] A method of manufacturing a substrate support for a substrate processing system includes: defining a vapor chamber cavity within a vapor chamber body; disposing a plurality of capillary structures on a surface within the vapor chamber cavity; and disposing the vapor chamber body between a base and a substrate.

[0017] Among other features, the method includes defining a fluid channel within the substrate, wherein the fluid channel is in thermal communication with a lower surface of the vapor chamber body. The method includes disposing the fluid channel in a spiral pattern. The method includes disposing a cover above the fluid channel and adjacent to the lower surface of the vapor chamber.

[0018] Among other features, the method includes: disposing the plurality of capillary structures on a lower surface of the vapor chamber; and supplying a working fluid within the vapor chamber body. The method includes: disposing the plurality of capillary structures on an upper surface of the vapor chamber; and supplying a working fluid within the vapor chamber body.

[0019] Among other features, the plurality of capillary structures include wicking materials that move the working fluid within the vapor chamber cavity by capillary action. The plurality of capillary structures include fabrics that move the working fluid within the vapor chamber cavity by capillary action. The plurality of capillary structures include sintered powder materials that move the working fluid within the vapor chamber cavity by capillary action. The plurality of capillary structures include grooved materials that move the working fluid within the vapor chamber cavity by capillary action.

[0020] Further scope of applicability of the present disclosure will become apparent from the detailed description, claims and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present disclosure will be more fully understood from the detailed description and the drawings, in which:

[0022] Figure 1 is a partial perspective view of a pedestal including a vapor chamber in accordance with the present disclosure;

[0023] Figure 2 is a cross-sectional view of a pedestal including a vapor chamber in accordance with the present disclosure; and

[0024] Figure 3 is a partial cross-sectional view of a pedestal including a vapor chamber in accordance with the present disclosure.

[0025] In the drawings, reference numerals may be reused to identify like and / or identical elements. DETAILED DESCRIPTION

[0026] In accordance with the present disclosure, a vapor chamber disposed below a pedestal is used to control the temperature of the pedestal.

[0027] Now referring to Figure 1 、 2 and 3, the pedestal temperature control system 10 includes a pedestal 12 and a vapor chamber 14 arranged to control the temperature of the pedestal 12. In some examples, the pedestal 12 includes a ceramic base material having a plated outer surface. In some examples, the ceramic material includes aluminum nitride (AlN), but other materials may also be used. In some examples, the pedestal may be an electrostatic chuck that uses electrostatic charge to hold a substrate in place during substrate processing, but mechanical or other types of chucks may be used.

[0028] In some examples, the vapor chamber 14 defines a vapor chamber cavity 15 in the form of a disk-shaped or flat columnar cavity. The vapor chamber cavity 15 of the vapor chamber 14 is defined by an upper surface 20, a lower surface 22, and sidewalls 24 disposed around the outer periphery of the flat columnar opening. The working fluid located in the vapor chamber 14 provides heating or cooling within the vapor chamber 14 as needed to increase temperature uniformity.

[0029] The inward-facing side of the lower surface 22 includes a plurality of capillary structures 26. By way of example only, the capillary structures 26 can include wicking materials, fabrics, powder materials such as metallic or non-metallic powders, grooved or other structures capable of moving fluids by capillary action. In some examples, metallic powders are sintered to the inner side of the lower surface 22 of the vapor chamber 14. As can be appreciated, the capillary structures 26 can also be formed on the inner side of the upper surface 20 and / or on the inner side of the sidewalls 24.

[0030] The base 32 can be disposed below the vapor chamber 14. In some examples, the base 32 can be made of aluminum. The base 32 can define fluid channels 40-1, 40-2... and 40-P, where P is an integer (collectively referred to as fluid channels 40). By way of example only, the fluid channels 40 can be arranged in a spiral pattern or any other suitable pattern. Water or another type of fluid can flow through the fluid channels 40 to provide heating or cooling. The tops of the fluid channels 40 can be enclosed by a cover 44. In some examples, the cover 44 is welded in place to seal the fluid channels 40.

[0031] A controller, one or more valves, one or more pumps, and thermocouples can be used to control the fluid source for heating and / or cooling. For example, in Figure 1 a temperature-controlled fluid supply source 62, a pump 64, and a valve 68 can be used to supply a fluid at a predetermined temperature above or below the temperature of the working fluid to the fluid channels 40.

[0032] One or more coils 50 can be provided to supply thermal energy to the base 32. A connector 52 can connect from the radial interior of the base 32 to one or more coils 50 adjacent to the outer periphery of the base. A gas (“backside gas”) can be supplied via a channel 60 to a substrate resting on the base 12. A lift pin assembly (not shown) can be used to lift the substrate from the base 12.

[0033] In operation, the vapor chamber 14 encloses the working fluid. For example, another fluid hotter than the lower surface 22 of the vapor chamber 14 can be supplied to the fluid channels 40 by a heated fluid source. The fluid in the fluid channels 40 supplies thermal energy to the lower surface 22 of the vapor chamber 14. The working fluid located in the vapor chamber 14 on the lower surface 22 will vaporize. The vapor will then disperse uniformly within the vapor chamber 14 and condense on cooler surfaces at a lower temperature. This action will raise the temperature of these cooler surfaces. At the same time, the working fluid on the capillary structures 26 will replace the working fluid that evaporates. In this example, the heating action of the working fluid will tend to make all surfaces in the vapor chamber 14 have a more uniform temperature.

[0034] As can be appreciated, the vapor chamber 14 can also perform cooling. In this application, the capillary structure is disposed on the top surface rather than the bottom surface of the vapor chamber. For example, another fluid cooler than the lower surface 22 of the vapor chamber 14 can be supplied to the fluid passage 40 through a cooled fluid source. The fluid in the fluid passage 40 cools the lower surface 22 of the vapor chamber 14. The working fluid located on the lower surface 22 of the vapor chamber 14 condenses into a liquid. The liquid moves to the hotter surface in the vapor chamber 14 by capillary action and evaporates on the hotter surface at a higher temperature. This action reduces the temperature of these hotter surfaces. At the same time, the working fluid on the capillary structure 26 replaces the working fluid that will evaporate. In this example, the cooling effect of the working fluid will tend to make all the surfaces in the vapor chamber 14 have a more uniform temperature.

[0035] According to the present disclosure, it achieves temperature uniformity on the surface of the base 12 by creating a hermetically sealed vapor chamber with a very high thermal conductivity below the surface of the base that conducts heat at a high rate. By way of example only, heat can be conducted at a rate of 8,000 - 20,000 watts per meter kelvin (W / mK). Note that the conductivity of aluminum is approximately 200 W / mK.

[0036] In use, the vapor carrying the thermal energy will automatically deposit on the lower temperature surface, or even a portion of the surface, within the vapor chamber, thereby forming a passive and continuous system that seeks thermal uniformity. The working fluid (such as water, alcohol, or other fluids) can be varied to suit the temperature range required for the base and / or the materials used to fabricate the vapor chamber. Thus, the need for many heating zones is reduced or eliminated.

[0037] The foregoing description is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses. The broad teachings of the present disclosure can be implemented in a variety of forms. Thus, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited because other modifications will become apparent after studying the drawings, the specification, and the appended claims. As used herein, the term "at least one of" A, B, and C should be interpreted using non-exclusive logical "OR" to mean logic (A or B or C). It should be understood that one or more steps within a method can be performed in a different order (or simultaneously) without changing the principles of the present disclosure.

Claims

1. A substrate support for a substrate processing system, comprising: A base including a ceramic substrate with its outer surface coated and having an upper surface and a lower surface; A base made of a metallic material; and A vapor chamber disposed between the base and the base, defining a vapor chamber cavity in the form of a sealed flat cylindrical cavity and including a plurality of capillary structures disposed on a surface within the vapor chamber cavity, Wherein the plurality of capillary structures cause a working fluid in the vapor chamber cavity to move by capillary action; Wherein the base includes a fluid passage thermally communicating with the lower surface of the vapor chamber, and a cover is arranged on top of the fluid passage and adjacent to the lower surface of the vapor chamber to seal the fluid passage; The substrate support further includes a fluid supply source configured to supply a fluid to the fluid passage, which fluid has a higher temperature than the working fluid according to the temperature of the base, so that the fluid in the fluid passage supplies heat energy to the lower surface of the steam chamber, or has a lower temperature than the working fluid to cool the lower surface of the steam chamber; Among them, The material of the steam chamber and the working fluid are selected according to the desired temperature range of the base; And Wherein the heat conduction rate of the steam chamber is several orders of magnitude higher than that of the metallic material of the base.

2. The substrate support according to claim 1, wherein the fluid passage is arranged in a spiral pattern.

3. The substrate support according to claim 1, wherein the working fluid is located in the vapor chamber, the plurality of capillary structures are arranged on the lower surface of the vapor chamber, and the fluid supply source is configured to supply a fluid having a higher temperature than the working fluid to the fluid passage, so that the working fluid on the plurality of capillary structures evaporates and condenses on a cooler surface of the vapor chamber cavity.

4. The substrate support according to claim 1, wherein the working fluid is located in the vapor chamber, the plurality of capillary structures are arranged on the upper surface of the vapor chamber, the fluid supply source is configured to supply a fluid having a lower temperature than the working fluid to the fluid passage, and the heat energy from the base causes the working fluid on the plurality of capillary structures to evaporate and condense on a cooler surface of the vapor chamber cavity.

5. The substrate support according to claim 1, wherein the plurality of capillary structures are arranged on at least one of the lower surface, upper surface and side wall of the vapor chamber cavity.

6. The substrate support according to claim 1, wherein the vapor chamber performs heating, and the plurality of capillary structures are arranged on the lower surface of the vapor chamber cavity.

7. The substrate support according to claim 1, wherein the vapor chamber performs cooling, and the plurality of capillary structures are arranged on the upper surface of the vapor chamber cavity.

8. The substrate support according to claim 1, wherein the plurality of capillary structures include a wicking material that causes a working fluid in the vapor chamber cavity to move by capillary action.

9. The substrate support according to claim 1, wherein the plurality of capillary structures comprise a fabric that moves the working fluid in the vapor chamber cavity by capillary action.

10. The substrate support according to claim 1, wherein the plurality of capillary structures comprise a sintered powder material that moves the working fluid in the vapor chamber cavity by capillary action.

11. The substrate support according to claim 1, wherein the plurality of capillary structures comprise a grooved material that moves the working fluid in the vapor chamber cavity by capillary action.

12. The substrate support according to claim 1, wherein the fluid supply source is configured to supply fluid to the fluid channel at a first temperature to heat the lower surface of the vapor chamber, and to supply fluid to the fluid channel at a second temperature to cool the lower surface of the vapor chamber, thereby controlling the temperature of the base.

13. A vapor chamber for a substrate support of a substrate processing system, comprising: a body comprising an upper surface, a lower surface, and side walls defining a vapor chamber cavity in the form of a sealed flat cylindrical cavity; and a plurality of capillary structures disposed on at least one of the upper surface, lower surface, and side walls within the vapor chamber cavity, wherein the vapor chamber is configured to be disposed between a base of the substrate support and a base portion, Among them, the base comprising a ceramic substrate having an outer surface with a plating, wherein the base portion is made of a metallic material, wherein the plurality of capillary structures move the working fluid in the vapor chamber cavity by capillary action; and wherein the lower surface of the vapor chamber is in thermal communication with a fluid channel contained in the base portion, and a cover is disposed on top of the fluid channel and adjacent to the lower surface of the vapor chamber to seal the fluid channel, and fluid is supplied to the fluid channel, and depending on the temperature of the base, the fluid has a higher temperature compared to the working fluid so that the fluid in the fluid channel supplies heat energy to the lower surface of the vapor chamber, and has a lower temperature compared to the working fluid to cool the lower surface of the vapor chamber, wherein the material of the vapor chamber and the working fluid are selected according to a desired temperature range of the base; and wherein the heat conduction rate of the vapor chamber is several orders of magnitude higher than the heat conduction rate of the metallic material of the base portion.

14. The vapor chamber according to claim 13, wherein: a working fluid is located in the vapor chamber, the vapor chamber supplies heat energy to the base, and the plurality of capillary structures are disposed on the lower surface of the vapor chamber to evaporate the working fluid and to condense the working fluid on a cooler surface within the vapor chamber cavity.

15. The vapor chamber according to claim 13, wherein: a working fluid is located in the vapor chamber, the vapor chamber performs cooling of the base, and the plurality of capillary structures are disposed on the upper surface of the vapor chamber to evaporate the working fluid and to condense the working fluid on a cooler surface within the vapor chamber cavity.

16. The vapor chamber according to claim 13, wherein the plurality of capillary structures comprise a wicking material that moves the working fluid in the vapor chamber cavity by capillary action.

17. The vapor chamber according to claim 13, wherein the plurality of capillary structures comprise a fabric that moves the working fluid in the vapor chamber cavity by capillary action.

18. The vapor chamber according to claim 13, wherein the plurality of capillary structures comprise a sintered powder material that moves the working fluid in the vapor chamber cavity by capillary action.

19. The vapor chamber according to claim 13, wherein the plurality of capillary structures comprise a grooved material that moves the working fluid in the vapor chamber cavity by capillary action.

20. A method for manufacturing a substrate support for a substrate processing system, comprising: defining a vapor chamber cavity within a vapor chamber body in the form of a sealed flat cylindrical cavity; disposing a plurality of capillary structures on the surface within the vapor chamber cavity; and disposing the vapor chamber body between a base and a pedestal, Among them, the pedestal including a ceramic substrate having an outer surface with a plating, wherein the pedestal is made of a metal material, wherein the plurality of capillary structures move the working fluid in the vapor chamber cavity by capillary action; the method further comprising: defining a fluid channel in the pedestal, wherein the fluid channel is in thermal communication with the lower surface of the vapor chamber body; disposing a lid on top of the fluid channel and adjacent to the lower surface of the vapor chamber to seal the fluid channel; supplying a fluid to the fluid channel, the fluid having a higher temperature than the working fluid according to the temperature of the pedestal, so that the fluid in the fluid channel supplies thermal energy to the lower surface of the steam chamber, or having a lower temperature than the working fluid to cool the lower surface of the steam chamber, selecting the material of the steam chamber and the working fluid according to the required temperature range of the pedestal; using the steam chamber to conduct heat, the heat conduction rate of the steam chamber being several orders of magnitude higher than the heat conduction rate of the metal material of the pedestal.

21. The method according to claim 20, further comprising arranging the fluid channel in a spiral pattern.

22. The method according to claim 20, further comprising: disposing the plurality of capillary structures on the lower surface of the vapor chamber; and supplying a working fluid within the vapor chamber body.

23. The method according to claim 20, further comprising: disposing the plurality of capillary structures on the upper surface of the vapor chamber; and supplying a working fluid within the vapor chamber body.

24. The method according to claim 20, wherein the plurality of capillary structures comprise a wicking material that moves the working fluid in the vapor chamber cavity by capillary action.

25. The method according to claim 20, wherein the plurality of capillary structures comprise a fabric that moves the working fluid in the vapor chamber cavity by capillary action.

26. The method according to claim 20, wherein the plurality of capillary structures comprises a sintered powder material that moves the working fluid in the vapor chamber by capillary action.

27. The method according to claim 20, wherein the plurality of capillary structures comprises a grooved material that moves the working fluid in the vapor chamber by capillary action.

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