Oxygen-containing ceramic hard masks and associated wet-cleans

Patent metadata

Field	Value
Publication number	US-9337068-B2
Application number	US-201314105026-A
Country	US
Kind code	B2
Filing date	Dec 12, 2013
Priority date	Dec 18, 2012
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

A method of forming an oxygen-containing ceramic hard mask film on a semiconductor substrate involves receiving a semiconductor substrate in a plasma-enhanced chemical vapor deposition (PECVD) process chamber and depositing forming by PEVCD on the substrate an oxygen-containing ceramic hard mask film, the film being etch selective to low-k dielectric and copper, resistant to plasma dry-etch and removable by wet-etch. The method may further involve removing the oxygen-containing ceramic hard mask film from the substrate with a wet etch. Corresponding films and apparatus are also provided.

First claim

What is claimed is:

1. A method of forming a hard mask film on a semiconductor substrate, the method comprising:
receiving a semiconductor substrate in a plasma-enhanced chemical vapor deposition (PECVD) process chamber; and
forming by PEVCD on the substrate an oxygen-containing ceramic hard mask film, the film being etch selective to copper, resistant to plasma dry-etch and removable by wet-etch;
wherein the film formation comprises,
flowing a process gas consisting essentially of He, C 2 H 2 , CO 2 and B 2 H 6 , and a carrier gas into the process chamber; and
forming plasma to deposit the oxygen-containing ceramic hard mask film consisting essentially of the elements C, H, B and at least 5% O on the substrate.

2. The method of claim 1 , wherein the percentage of precursors relative to total process gas flow is about He 80-83%/C 2 H 2 10-11%/CO 2 5-8%/B 2 H 6 2-3%.

3. The method of claim 2 , wherein the percentage of precursors relative to total process gas flow is about He 82%/C 2 H 2 10.5%/CO 2 5%/B 2 H 6 2.5%.

4. The method of claim 2 , wherein the percentage of precursors relative to total process gas flow is about He 80%/C 2 H 2 10%/CO 2 7.5%/B 2 H 6 2.5%.

5. The method of claim 1 , wherein the total flow of precursor process gas is about 10000 sccm.

6. The method of claim 1 , further comprising removing the oxygen-containing ceramic hard mask film from the substrate with a wet etch.

7. The method of claim 6 , where in the wet etch chemistry comprises an oxidant and a strong acid or base compound.

8. The method of claim 7 , wherein the wet etch chemistry further comprises a metal corrosion inhibitor.

9. The method of claim 6 , where in the wet etch chemistry comprises water.

10. The method of claim 9 , wherein the wet etch chemistry further comprises a metal corrosion inhibitor.

11. The method of claim 1 , wherein the formed hard mask layer is deposited over a layer of dielectric having a dielectric constant of less than about 2.8, and wherein the formed hard mask film has an etch selectivity of at least about 8:1 versus the dielectric in a dry plasma etch.

12. The method of claim 1 , wherein the formed hard mask layer is deposited over a layer of polysilicon.

13. The method of claim 1 , wherein the wet etch chemistry comprises 1:1 96% H 2 SO 4 :30% H 2 O 2 .

14. An apparatus for processing a hard mask film on a semiconductor substrate, the apparatus comprising:
a plasma-enhanced chemical vapor deposition (PECVD) process chamber;
a support in the process chamber for a semiconductor wafer substrate for holding the wafer substrate in position during hard mask deposition; and
a controller comprising program instructions for a process of:
receiving a semiconductor wafer substrate in a plasma-enhanced chemical vapor deposition (PECVD) process chamber; and
forming by PEVCD on the substrate an oxygen-containing ceramic hard mask film, the film being etch selective to copper, resistant to plasma dry-etch and removable by wet-etch, and wherein the film formation comprises,
flowing a process gas consisting essentially of He, C 2 H 2 , CO 2 and B 2 H 6 , and a carrier gas into the process chamber; and
forming plasma to deposit the oxygen-containing ceramic hard mask film consisting essentially of the elements C, H, B and at least 5% O on the substrate.

15. The apparatus of claim 14 , further comprising:
a wet etch process chamber; and
a controller comprising program instructions for a process of:
receiving the semiconductor wafer substrate with the oxygen-containing ceramic hard mask film formed thereon; and
removing the oxygen-containing ceramic hard mask film from the substrate with a wet etch.

16. The apparatus of claim 14 , wherein the wet etch chemistry comprises 1:1 96% H 2 SO 4 : 30% H 2 O 2 .

Assignees

• Lam Res Corp

Inventors

• Antonelli George Andrew
• Hollister Alice
• Reddy Sirish

Classifications

• H10P72/0606

  Position monitoring, e.g. misposition detection or presence detection · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P50/73

  using masks for insulating materials · CPC title

• H10P50/71

  using masks for conductive or resistive materials · CPC title

• H10P14/6336

  in the presence of a plasma [PECVD] · CPC title