VARIABLE DEPTH EDGE RING FOR ETCH UNIFORMITY CONTROL

• US 20170236741A1
• Filed: 02/02/2017
• Published: 08/17/2017
• Est. Priority Date: 02/12/2016
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Angelov, Ivelin, Siladie, Cristian, Severson, Brian, Larson, Dean
• Granted Patent: US 10,651,015 B2
• Time in Patent Office: Days
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01J 37/00 Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof H01J33/00, H01J40/00, H01J41/00, H01J47/00, H01J49/00 take precedence
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32715 Workpiece holder

Abstract

A substrate support includes an inner portion arranged to support a substrate, an edge ring surrounding the inner portion, and a controller that calculates a desired pocket depth of the substrate support. Pocket depth corresponds to a distance between an upper surface of the edge ring and an upper surface of the substrate. Based on the desired pocket depth, the controller selectively controls an actuator to raise and lower at least one of the edge ring and the inner portion to adjust the distance between the upper surface of the edge ring and the upper surface of the substrate.

Claims

1. A substrate support, comprising:

an inner portion arranged to support a substrate;

an edge ring surrounding the inner portion; and

a controller that

calculates a desired pocket depth of the substrate support, wherein pocket depth corresponds to a distance between an upper surface of the edge ring and an upper surface of the substrate, and

based on the desired pocket depth, selectively controls an actuator to raise and lower at least one of the edge ring and the inner portion to adjust the distance between the upper surface of the edge ring and the upper surface of the substrate.

2. The substrate support of claim 1, wherein the edge ring is arranged on an outer portion of the substrate support and, to raise and lower the edge ring, the controller controls the actuator to raise and lower the outer portion.

3. The substrate support of claim 1, wherein the edge ring includes an inner ring portion that is moveable independently of the edge ring.

4. The substrate support of claim 1, wherein the inner portion corresponds to an electrostatic chuck.

5. The substrate support of claim 1, wherein the actuator raises and lowers the at least one of the edge ring and the inner portion using one or more actuator pins.

6. The substrate support of claim 1, wherein the controller calculates the desired pocket depth based on at least one process parameter, wherein the process parameter includes at least one of a selected recipe or process to be performed on the substrate, characteristics of a processing chamber, a thickness of the substrate, a desired gas velocity profile, and a desired etch uniformity.

7. The substrate support of claim 6, wherein the controller includes a pocket depth calculation module that receives at least one input indicative of the process parameter and calculates the desired pocket depth based on the input.

8. The substrate support of claim 7, further comprising a memory that stores data indicative of a relationship between the process parameter and the desired pocket depth.

9. The substrate support of claim 8, wherein the pocket depth calculation module (i) retrieves the data from the memory based on the input and (ii) calculates the desired pocket depth based on the retrieved data.

10. The substrate support of claim 9, wherein the pocket depth calculation module calculates the desired pocket depth further based on at least one of a model and a lookup table stored in the memory.

11. A method of operating a substrate support, the method comprising:

arranging a substrate on an inner portion of the substrate support;

calculating a desired pocket depth of the substrate support, wherein pocket depth corresponds to a distance between an upper surface of an edge ring surrounding the inner portion and an upper surface of the substrate; and

based on the desired pocket depth, selectively controlling an actuator to raise and lower at least one of the edge ring and the inner portion to adjust the distance between the upper surface of the edge ring and the upper surface of the substrate.

12. The method of claim 11, wherein the edge ring is arranged on an outer portion of the substrate support and, wherein raising and lowering the edge ring includes controlling the actuator to raise and lower the outer portion.

13. The method of claim 11, wherein the edge ring includes an inner ring portion that is moveable independently of the edge ring.

14. The method of claim 11, wherein the inner portion corresponds to an electrostatic chuck.

15. The method of claim 11, wherein raising and lowering the at least one of the edge ring and the inner portion includes using one or more actuator pins.

16. The method of claim 11, wherein calculating the desired pocket depth includes calculating the desired pocket depth based on at least one process parameter, wherein the process parameter includes at least one of a selected recipe or process to be performed on the substrate, characteristics of a processing chamber, a thickness of the substrate, a desired gas velocity profile, and a desired etch uniformity.

17. The method of claim 16, further comprising receiving at least one input indicative of the process parameter and calculating the desired pocket depth based on the input.

18. The method of claim 17, further comprising storing, in memory, data indicative of a relationship between the process parameter and the desired pocket depth.

19. The method of claim 18, further comprising retrieving the data from the memory based on the input and calculating the desired pocket depth based on the retrieved data.

20. The method of claim 19, further comprising calculating the desired pocket depth further based on at least one of a model and a lookup table stored in the memory.