Multi-plate electrostatic chucks with ceramic baseplates
Patent Information
- Authority / Receiving Office
- TW · TW
- Patent Type
- Patents
- Current Assignee / Owner
- LAM RES CORP
- Filing Date
- 2019-02-19
- Publication Date
- 2026-08-01
AI Technical Summary
Conventional electrostatic chucks (ESC) face issues with thermal mismatch and arcing due to the use of different materials for the top and bottom plates, which limits their operational range and reliability under high RF voltages and temperature changes.
The ESC design incorporates both the top and bottom plates made of ceramic materials with precise control over purity, minimizing thermal expansion differences and eliminating the risk of coating disintegration and cracking, thereby enhancing the ESC's ability to handle high RF voltages and maintain temperature stability.
The ceramic-based ESCs provide improved thermal stability, increased operational temperature range, and enhanced control over RF voltage distribution, ensuring reliable substrate handling and processing performance.
Smart Images
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Abstract
Description
[Technical Field] This invention relates to an electrostatic chuck for a substrate processing system. [Previous Technology] The prior art description provided herein is intended to generally introduce the background of this invention. The achievements of the inventors named in this application within the scope of the prior art section, as well as embodiments of the specification that were not worthy of prior art at the time of application, are not intended or implied to be considered prior art against this invention. Substrate processing systems can be used to perform etching, deposition, and / or other processing on substrates (e.g., semiconductor wafers). Example processing that can be performed on a substrate includes (but is not limited to) plasma-assisted chemical vapor deposition (PECVD), physical vapor deposition (PVD), ion implantation, and / or other etching, deposition, and cleaning processes. For example, during an etching process, the substrate can be placed on an electrostatic chuck (ESC) in the substrate processing system, and a thin film on the substrate can be etched. [Summary of the Invention] An electrostatic chuck for a substrate processing system is provided. The electrostatic chuck includes: a top plate configured to electrostatically clamp a substrate and formed of ceramic; an intermediate layer disposed below the top plate; and a bottom plate disposed below the intermediate layer and formed of ceramic. The intermediate layer bonds the top plate to the bottom plate. Among other characteristics, the ceramic purity of the base plate is greater than or equal to 90%. Among other characteristics, the ceramic purity of the base plate is greater than or equal to 95%. Among other characteristics, the ceramic purity of the base plate is greater than or equal to 99.9%. Among other features, the base plate includes a base layer and a protective coating disposed on the base layer. The protective coating is disposed between the base layer and the intermediate layer. Among other features, the base plate includes a first portion and a second portion. The first portion projects upward from the second portion. The intermediate layer and the top plate are disposed on the first portion. Among other features, the base plate includes one or more gas channels. These one or more gas channels are located below the top plate. Among other features, the base plate comprises a first layer and a second layer. The first layer is disposed above the second layer. The first layer contains a first set of gas channels. The second layer contains a second set of gas channels. Among other features, the substrate includes a plurality of radio frequency (RF) electrodes. Among other features, the substrate includes one or more gas channels. One or more of the plurality of RF electrodes are disposed in the substrate and above the one or more gas channels. Among other features, the base plate includes a first portion and a second portion. The first portion protrudes upward from the second portion. One or more of the plurality of RF electrodes are disposed in the base plate and radially outward from the first portion. Among other features, the electrostatic chuck further includes an edge ring disposed on the base plate and at least partially disposed radially outward of the top plate. The base plate includes a protrusion extending upward toward the top plate. The protrusion centers the edge ring on the base plate. Among other features, one or more of the plurality of RF electrodes are disposed in the base plate and below the edge ring. In other features, the electrostatic chuck further includes an edge ring disposed on the base plate and radially outward of the top plate. In other features, the electrostatic chuck further includes an edge ring disposed on the base plate and at least partially disposed radially outward of the top plate. The edge ring includes a radio frequency electrode or an electrostatic clamping electrode. In other features, the top plate includes one or more electrostatic clamping electrodes. In other features, the top plate includes one or more heating elements. In other features, the base plate includes one or more DC electrodes. Among other features, the base plate includes a plurality of coolant channels. Among other features, at least one of the plurality of coolant channels is arranged in a dual-channel configuration. Among other features, at least one of the plurality of coolant channels is arranged in a single-channel configuration. Among other features, the base plate includes a first layer and a second layer. The plurality of coolant channels includes a first group of coolant channels and a second group of coolant channels. The first layer includes the first group of coolant channels. The second layer includes the second group of coolant channels. Among other features, the electrostatic chuck further includes a gas channel extending from the bottom of the base plate to an outlet in the top plate. The gas channel contains at least one porous medium. Among other features, the electrostatic chuck further includes an annular seal disposed radially outside the intermediate layer and providing protection for the intermediate layer. Among other features, a substrate processing system is provided, comprising a processing chamber, an electrostatic chuck, a temperature sensor, and a control module. The electrostatic chuck is disposed in the processing chamber. The electrostatic chuck includes one or more temperature adjustment elements. The temperature sensor is disposed in at least one of a top plate or a bottom plate and is configured to detect the temperature of the top plate. The control module is configured to receive the output of the temperature sensor and, based on the output of the temperature sensor, control the operation of an actuator to adjust the one or more temperature adjustment elements to adjust the temperature of at least one of the top plate or the bottom plate. Among other features, the one or more temperature regulating elements include at least one of a heating element, a gas passage, or a coolant passage; and the actuator is a power source, a coolant pump, a gas pump, or a valve. Among other features, the temperature sensor is disposed in the base plate and configured to detect the temperature of the base plate. Among other features, the substrate processing system further includes an edge ring and a radio frequency (RF) electrode. The edge ring is disposed on the base plate and is at least partially disposed radially outward of the top plate. The RF electrode is disposed in the base plate and below the edge ring. A temperature sensor is disposed in the base plate and configured to detect the temperature of a region of the base plate. This region of the base plate is located below the edge ring. Further applicability of this disclosure will become apparent from the embodiments, the scope of the invention claims, and the drawings. The detailed descriptions and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure.
Implementation Method
Claims
1. An electrostatic chuck for a substrate processing system, comprising: a top plate configured to electrostatically clamp a substrate and formed of ceramic; an intermediate layer disposed below the top plate; and a bottom plate disposed below the intermediate layer and formed of ceramic, wherein the intermediate layer bonds the top plate to the bottom plate, the bottom plate including a plurality of radio frequency (RF) electrodes configured for RF plasma generation, the bottom plate including one or more gas channels, the bottom plate including a first portion and a second portion; the first portion projecting upward from the second portion; the one or more gas channels being at least partially disposed in the first portion, and one or more of the plurality of RF electrodes being embedded in the first portion of the bottom plate and above the one or more gas channels.
2. The electrostatic chuck for a substrate processing system as described in claim 1, wherein the ceramic purity of the substrate is greater than or equal to 90%.
3. The electrostatic chuck for a substrate processing system as described in claim 1, wherein the ceramic purity of the substrate is greater than or equal to 95%.
4. The electrostatic chuck for a substrate processing system as described in claim 1, wherein the ceramic purity of the substrate is greater than or equal to 99.9%.
5. The electrostatic chuck for a substrate processing system as described in claim 1, wherein: The base plate includes a base layer and a protective coating disposed on the base layer; and the protective coating is disposed between the base layer and the intermediate layer.
6. The electrostatic chuck for a substrate processing system as described in claim 1, wherein: The intermediate layer and the top plate are disposed on the first part.
7. The electrostatic chuck for a substrate processing system as claimed in claim 1, wherein one or more gas channels are disposed below the top plate.
8. The electrostatic chuck for a substrate processing system as described in claim 1, wherein: The base plate includes a first layer and a second layer; the first layer is disposed above the second layer; the first layer includes a first set of gas channels; the second layer includes a second set of gas channels; and the one or more gas channels include the first set of gas channels and the second set of gas channels.
9. The electrostatic chuck for a substrate processing system as described in claim 1, wherein: At least one of the plurality of RF electrodes is disposed in the base plate and on the radially outer side of the first portion.
10. The electrostatic chuck for a substrate processing system as claimed in claim 1 further includes an edge ring disposed on the base plate and at least partially disposed radially outward of the top plate, wherein: The base plate includes a protruding portion that extends upward toward the top plate; Furthermore, the protruding portion centers the edge ring on the base plate.
11. The electrostatic chuck for a substrate processing system as claimed in claim 10, wherein at least one of the plurality of RF electrodes is disposed in the base plate and below the edge ring.
12. The electrostatic chuck for a substrate processing system as claimed in claim 1 further includes an edge ring disposed on the base plate and centered on the top plate and radially outward from the top plate.
13. The electrostatic chuck for a substrate processing system as claimed in claim 1 further includes an edge ring disposed on the base plate and at least partially disposed on the radially outer side of the top plate, wherein the edge ring includes a radio frequency electrode or an electrostatic clamping electrode.
14. The electrostatic chuck for a substrate processing system as claimed in claim 1, wherein the top plate includes one or more electrostatic clamping electrodes.
15. The electrostatic chuck for a substrate processing system as claimed in claim 1, wherein the top plate includes one or more heating elements.
16. The electrostatic chuck for a substrate processing system as claimed in claim 1, wherein the top plate includes one or more DC electrodes.
17. The electrostatic chuck for a substrate processing system as claimed in claim 1, wherein the base plate includes a plurality of coolant channels below the one or more gas channels.
18. The electrostatic chuck for a substrate processing system as claimed in claim 17, wherein at least one of the plurality of coolant channels is configured in a dual-strand configuration.
19. The electrostatic chuck for a substrate processing system as claimed in claim 17, wherein at least one of the plurality of coolant channels is configured as a single strand.
20. The electrostatic chuck for a substrate processing system as described in claim 17, wherein: The base plate includes a first layer and a second layer, with the second layer disposed on top of the first layer; the plurality of coolant channels includes a first group of coolant channels and a second group of coolant channels; the first layer includes the first group of coolant channels; and the second layer includes the second group of coolant channels.
21. The electrostatic chuck for a substrate processing system as claimed in claim 1 further includes a gas channel extending from the bottom of the base plate to an outlet in the top plate, wherein: The gas passage contains at least one porous medium; and the one or more gas passages include the gas passage extending from the bottom of the base plate to an outlet in the top plate.
22. The electrostatic chuck for a substrate processing system as claimed in claim 1 further comprises: an edge ring disposed on the base plate and at least partially disposed radially outward of the top plate, wherein the base plate includes a protrusion extending upward toward the top plate and the protrusion centered the edge ring on the base plate; and a single annular seal disposed radially outward of the radial outer edge of the intermediate layer and providing protection for the radial outer edge of the intermediate layer, and between the edge ring and the base plate, and contacting both the edge ring and the base plate.
23. The electrostatic chuck for a substrate processing system as claimed in claim 1, wherein the plurality of RF electrodes are disposed in the upwardly projecting portion of the base plate.
24. The electrostatic chuck for a substrate processing system as claimed in claim 1, wherein the second portion includes one or more liquid coolant channels disposed below the one or more gas channels.
25. The electrostatic chuck for a substrate processing system as described in claim 1, wherein: The plurality of RF electrodes and the one or more gas channels are disposed in the upwardly protruding portion of the base plate; Furthermore, the base plate includes one or more liquid coolant channels disposed below the one or more gas channels.
26. The electrostatic chuck for a substrate processing system as claimed in claim 5, wherein the protective coating is formed of ceramic.
27. The electrostatic chuck for a substrate processing system as claimed in claim 9, wherein the base plate includes at least partially disposed in the first portion of the one or more gas channels.
28. The electrostatic chuck for a substrate processing system as claimed in claim 27, wherein the base plate includes one or more coolant channels disposed in the second part.
29. The electrostatic chuck for a substrate processing system as claimed in claim 28, wherein the one or more coolant channels circulate a liquid coolant.
30. The electrostatic chuck for a substrate processing system as described in claim 9, wherein: The complex RF electrode system is disposed on the radial outer side of the first part.
31. The electrostatic chuck for a substrate processing system as claimed in claim 9, wherein two or more of the plurality of RF electrodes are embedded in the base plate and radially outward of the first portion.
32. The electrostatic chuck for a substrate processing system as claimed in claim 18, wherein one of the plurality of coolant channels begins at a first point near the center of the substrate, coils in a circular loop pattern to the periphery of the substrate, and extends from the periphery of the substrate back in a loop pattern to a second point near the center of the substrate.
33. The electrostatic chuck for a substrate processing system as claimed in claim 22, wherein the annular seal covers the radial outer edge of the intermediate layer.
34. The electrostatic chuck for a substrate processing system as described in claim 1, wherein: The first portion has a diameter smaller than the outer diameter of the base plate and the outer diameter of the top plate; the top plate has an outer diameter smaller than the outer diameter of the base plate; and one or more of the plurality of RF electrodes are embedded in the first portion of the base plate and above the one or more gas channels.
35. The electrostatic chuck for a substrate processing system as claimed in claim 1, wherein the top plate has a smaller diameter than the outer diameter of the bottom plate.
36. An electrostatic chuck for a substrate processing system, comprising: a top plate configured to electrostatically clamp a substrate and formed of ceramic; an intermediate layer disposed below the top plate; and a bottom plate disposed below the intermediate layer and formed of ceramic, wherein the intermediate layer bonds the top plate to the bottom plate, the bottom plate including a plurality of radio frequency (RF) electrodes configured for RF plasma generation, the bottom plate including one or more gas channels, one or more of the plurality of RF electrodes being embedded in the bottom plate and above the one or more gas channels, the bottom plate including a first portion and a second portion; the first portion projecting upward from the second portion; one or more of the plurality of RF electrodes being disposed in the bottom plate and radially outward of the second portion, and not disposed below the first portion of the top plate.
37. A substrate processing system comprising: a processing chamber; an electrostatic chuck, as claimed in claim 1, disposed in the processing chamber, wherein the electrostatic chuck includes one or more temperature adjustment elements; an edge ring disposed on a base plate and at least partially disposed radially outward of a top plate, wherein at least one of the plurality of RF electrodes is disposed in a second portion of the base plate and below the edge ring; a temperature sensor disposed in at least one of the top plate or the base plate and configured to detect the temperature of the top plate; and a controller configured to receive the output of the temperature sensor and, based on the output of the temperature sensor, control the operation of an actuator to adjust the temperature of the one or more temperature adjustment elements, thereby adjusting the temperature of the at least one of the top plate or the base plate.
38. The substrate processing system of claim 37, wherein: The one or more temperature regulating elements include at least one of the following: a heating element, the one or more gas passages, or a coolant passage; Furthermore, the actuator can be a power source, a coolant pump, a gas pump, or a valve.
39. The substrate processing system of claim 37, wherein the temperature sensor is disposed in the substrate and configured to detect the temperature of the substrate.
40. The substrate processing system of claim 37, wherein the temperature sensor is disposed in the substrate and configured to detect the temperature of a region of the substrate, and the region of the substrate is located below the edge ring.
41. The substrate processing system of claim 37, wherein: At least one of the plurality of RF electrodes is not located below the top plate.