Plasma etch resistant coating and process

• US 20030215963A1
• Filed: 05/17/2002
• Published: 11/20/2003
• Est. Priority Date: 05/17/2002
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM America Incorporated (ASM International NV)
• Inventors: Pomarede, Christophe, AmRhein, Fred
• Granted Patent: US 6,825,051 B2
• Time in Patent Office: Days
• US Class Current: 438/9
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: C23C 16/4581 characterised by material of construction or surface finish of the means for supporting the substrate
• CPC Class Codes: C23C 16/481 by radiant heating of the substrate
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/68757 characterised by a coating or a hardness or a material

Abstract

A protective coating is provided herein and methods of using the protective coating for susceptors used in semiconductor deposition chambers are described. In the preferred embodiments, CVD chamber equipment, such as a susceptor, is protected from plasma etch cleaning. Prior to CVD of silicon nitride, the chamber equipment is first coated with an emissivity-stabilizing layer, such as silicon nitride. This layer is then superficially oxidized. After repeated cycles of deposited silicon nitride upon different substrates in sequence, the chamber is emptied of wafers and a plasma cleaning process is conducted. Plasma cleaning is preferably selective against the silicon oxynitride protective coating. After the plasma cleaning process, the emissivity-stabilizing layer is reapplied, oxidized, and a plurality of deposition cycles can commence again.

Claims

1. A susceptor for a semiconductor reactor configured for plasma etch processing, the susceptor comprising a silicon oxynitride coating.

2. The susceptor of claim 1 wherein the susceptor is a SiC-coated graphite susceptor.

3. The susceptor of claim 1 wherein the reactor is configured for silicon nitride deposition.

4. The susceptor of claim 3 wherein the reactor is configured for plasma cleaning of reactor surfaces after a plurality of cycles of silicon nitride deposition.

5. A method of preparing a substrate holder for deposition, comprising:

providing a substrate holder in a chemical vapor deposition chamber;

coating the substrate holder with a primary coating of silicon nitride in the chamber; and

oxidizing the primary substrate coating on the substrate holder prior to processing of substrates.

6. The method of claim 5 wherein coating the substrate holder with the primary coating comprises chemical vapor deposition of silicon nitride.

8. The method of claim 5 wherein oxidizing comprises flowing an oxygen source selected from the group consisting of oxygen, nitric oxide, and nitrous oxide.

9. The method of claim 5 wherein the primary silicon nitride coating has a thickness between about 500 Å

and 2.0 μ

m.

10. The method of claim 5 wherein oxidizing forms between about 5 Å

and 200 Å

of silicon oxynitride.

11. The method of claim 5 wherein oxidizing comprises oxidizing the primary coating nonuniformly across a non-rotating component within the chamber.

7. The method of claim 7 wherein coating the substrate holder with the primary coating comprises supplying a mixture of a silicon source gas and ammonia.

12. The method of claim 12 wherein non-uniformly oxidizing comprises providing an inert gas to direct an oxygen source non-uniformly over the non-rotating component.

13. The method of claim 12 wherein non-uniformly oxidizing comprises adjusting temperature offsets.

14. A process of depositing silicon nitride, comprising:

providing an oxidized silicon nitride coating on a susceptor;

depositing silicon nitride on a plurality of substrates in sequence upon the coated susceptor; and

plasma cleaning silicon nitride from the susceptor after depositing.

15. A method of processing semiconductor substrates, comprising:

preparing a susceptor by providing an emissivity-stabilizing coating over the susceptor and oxidizing the emissivity-stabilizing coating prior to processing of substrates;

loading a substrate onto the coated and oxidized susceptor;

depositing a layer of a material onto the substrate and at least portions of the susceptor;

removing the substrate from the susceptor after depositing; and

plasma cleaning of the deposited material from the susceptor.

16. The method of claim 15 wherein the emissivity-stabilizing coating comprises silicon nitride.

17. The method of claim 15 wherein loading the substrate, depositing the layer of the material onto the substrate, and removing the substrate from the susceptor are repeated 5 to 1000 times prior to plasma cleaning.

18. The method of claim 17, wherein depositing the layer of the material comprises depositing 10 Å

to 50 Å

of silicon nitride on each substrate.

19. The method of claim 15, wherein plasma cleaning comprises providing etchant gases through an upstream excited species generator.

20. The method of claim 19, wherein plasma cleaning selectively removes silicon nitride from over silicon oxynitride.

21. The method of claim 19, wherein plasma cleaning is performed before the deposits are greater than about 2 μ

m in thickness.