Sulfur doped carbon hard masks

• US 9,320,387 B2
• Filed: 05/05/2014
• Issued: 04/26/2016
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Reddy, Sirish K., Hollister, Alice G., Lill, Thorsten
• Primary Examiner(s): Lee, Kyoung
• Application Number:
  US14/270,001
• Publication Number:
  US 20150093915A1
• Time in Patent Office: 722 Days
• US Class Current: 1/1
• CPC Class Codes: A47J 2203/00 Devices having filling level indicating means
• CPC Class Codes: A47J 31/60 Cleaning devices
• CPC Class Codes: B65D 65/466 Bio- or photodegradable packaging materials
• CPC Class Codes: C11D 17/041 Compositions releasably affixed on a substrate or incorporated into a dispensing means
• CPC Class Codes: C11D 17/046 Insoluble free body dispenser
• CPC Class Codes: C11D 2111/20 Industrial or commercial equipment, e.g. reactors, tubes or engines
• CPC Class Codes: C11D 3/3942 Inorganic per-compounds C11D3/3902 takes precedence
• CPC Class Codes: C11D 7/12 Carbonates bicarbonates
• CPC Class Codes: H01L 21/0271 comprising organic layers

Abstract

Provided are methods of forming ashable hard masks (AHMs) with high etch selectivity and low hydrogen content using plasma enhanced chemical vapor deposition. Methods involve exposing a first layer to be etched on a semiconductor substrate to a carbon source and sulfur source, and generating a plasma to deposit a sulfur-doped AHM or amorphous carbon-based film on the first layer.

Claims

1. A method of forming an ashable hard mask on a first layer to be etched on a semiconductor substrate, comprising:

providing a precursor gas comprising a carbon source and a sulfur source to a deposition chamber housing the semiconductor substrate, and

generating a plasma from the precursor gas to thereby deposit a sulfur-doped ashable hard mask on the first layer by a plasma enhanced chemical vapor deposition (PECVD) process.

2. The method of claim 1, wherein the deposited sulfur-doped ashable hard mask has an atomic sulfur content of between about 0.5% and about 5%.

3. The method of claim 2, wherein the deposited sulfur-doped ashable hard mask has an atomic carbon content of between about 60% and about 90%.

4. The method of claim 2, wherein the deposited sulfur-doped ashable hard mask has an atomic hydrogen content of between about 13% and about 26%.

5. The method of claim 1, wherein the sulfur-doped ashable hard mask is between about 1000 Å

and about 90,000 Å

thick.

6. The method of claim 1, wherein the sulfur-doped ashable hard mask has a stress of between about −

40 MPa and about −

400 MPa.

7. The method of claim 1, wherein the first layer is selected from the group consisting of an oxide layer, a nitride layer, and a polysilicon layer.

8. The method of claim 1, wherein the carbon source is methane, acetylene, or propylene.

9. The method of claim 1, wherein the sulfur source is hydrogen sulfide (H₂S) or carbon disulfide (CS₂).

10. The method of claim 1, wherein the sulfur source is carbon disulfide (CS₂) and the carbon source is acetylene (C₂H₂).

11. The method of claim 1, wherein the carbon source and sulfur source are combined upstream from the deposition chamber.

12. The method of claim 1, wherein the carbon source and the sulfur source are provided separately to the deposition chamber.

13. The method of claim 1, further comprising patterning the sulfur-doped ashable hard mask layer.

14. The method of claim 13, further comprising etching the first layer in accordance with the pattern of the sulfur-doped ashable hard mask.

15. A method of forming a sulfur-doped amorphous carbon-based film on a semiconductor substrate, comprising:

providing the semiconductor substrate in a deposition chamber,

exposing the semiconductor substrate to a precursor gas comprising a carbon source and a sulfur source, and

depositing a sulfur-doped amorphous carbon-based film on the semiconductor substrate by a plasma enhanced chemical vapor deposition (PECVD) process.

16. The method of claim 15, wherein the sulfur-doped amorphous carbon-based film has an atomic sulfur content of between about 0.5% and about 5%.

17. The method of claim 15, wherein the sulfur source is hydrogen sulfide (H₂S) or carbon disulfide (CS₂).