Ex situ coating of chamber components for semiconductor processing
Forming a protective coating ex situ in an atomic layer deposition process to coat one or more chamber components subsequently installed in a reaction chamber provides a number of benefits over more conventional coating methods such as in situ deposition of an undercoat. In certain cases the protective coating may have a particular composition such as aluminum oxide, aluminum fluoride, aluminum nitride, yttrium oxide, and/or yttrium fluoride. The protective coating may help reduce contamination on wafers processed using the coated chamber component. Further, the protective coating may act to stabilize the processing conditions within the reaction chamber, thereby achieving very stable/uniform processing results over the course of processing many batches of wafers, and minimizing radical loss. Also described are a number of techniques that may be used to restore the protective coating after the coated chamber component is used to process semiconductor wafers.
1. A method comprising:
(a) exposing a chamber component of a process chamber having an atomic layer deposition (ALD)-deposited metal nitride film thereon to a conditioning process comprising a nitrogen-containing plasma to form a conditioned metal nitride film, wherein the conditioned metal nitride film has a maximum compressive stress up to 500 MPa; and
(b) depositing film on a plurality of wafers within the process chamber.
2. The method of claim 1 , wherein the (a) is performed without a wafer in the process chamber.
3. The method of claim 1 , wherein the chamber component is a consumable chamber component.
4. The method of claim 1 , wherein the nitrogen-containing plasma comprises hydrogen species.
5. The method of claim 1 , wherein the film deposited in (b) is deposited by atomic layer deposition (ALD).
6. The method of claim 1 , wherein the nitrogen-containing plasma is generated nitrogen gas (N2).
7. The method of claim 1 , wherein the nitrogen-containing plasma is generated from ammonia (NH3).
8. The method of claim 1 , wherein the nitrogen-containing plasma is generated from hydrazine (N2H4).
9. The method of claim 1 , wherein the nitrogen-containing plasma is generated from a process gas comprising a nitrogen-containing compound and an inert gas.
10. The method of claim 9 , wherein the inert gas is argon (Ar).
11. The method of claim 1 , wherein the nitrogen-containing plasma has a frequency of 10-20 MHz.
12. The method of claim 1 , wherein a duration of the nitrogen-containing plasma is less than 10 minutes.
13. The method of claim 1 , further comprising repeating (a).
14. The method of claim 13 , wherein the number of wafers on which film is deposited in (b) is between 5 and 50 before (a) is repeated.
15. The method of claim 1 , wherein the component is a showerhead.
16. The method of claim 1 , wherein the component is a lift pin or lift pin holder.
17. The method of claim 1 , wherein the component is a substrate support.
18. A method comprising:
(a) exposing a chamber component of a process chamber having an atomic layer deposition (ALD)-deposited metal nitride film thereon to a plasma comprising a reactive nitrogen species to form a conditioned metal nitride film, wherein the conditioned metal nitride film has a maximum compressive stress up to 500 MPa; and
(b) after (a), depositing film on a plurality of wafers within the process chamber.
19. The method of claim 18 , wherein the plasma in (a) is generated from a process gas comprising a hydrogen-containing compound.