US5869404A
Expired / Lapsed
US
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Method for forming contact hole of semiconductor device
Assignee: Mosaid Technologies Inc
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Filing: 1997-04-25
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Granted: 1999-02-09
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Expires: 2017-04-25
Abstract
Abstract A method for forming a contact hole of semiconductor device is disclosed and comprises forming a word line and a first internal insulating film on a semiconductor substrate, forming an insulating film spacer at the side wall of the word line and the first internal insulating film, forming a nitride film as a second internal insulating film at a predetermined thickness on the resultant structure, forming a planarization layer on the second internal insulating film, etching the planarization layer in an atmosphere comprising C 4 F 8 gas, Ar gas and a hydrogen-containing gas in the presence of a contact mask, to create a contact hole through which the second internal insulating film is exposed. The hydrogen-containing gas acts to generate C--H type polymers weaker in bond strength but at a larger amount than C--C type polymers, thereby preventing the etching stop phenomenon as well as the underlying layer damage caused by overetch during the etching process of a contact hole. This allows the contact hole to be formed without increasing junction leakage current, resulting in a significant improvement in the reliability and the high integration of a semiconductor device.
Inventors
- 👤 Jeong Ho Kim
- 👤 Jin Woong Kim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:06
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
170 words
A method for forming a hole of a semiconductor device, comprising: forming a word line and a first internal insulating film on a semiconductor substrate; forming an insulating film spacer at a side wall of the word line and the first insulating film so as to form a resulting structure; forming a nitride film as a second internal insulating film on the resulting structure; forming a planarization layer on the second internal insulating film; in an atmosphere including C 4 F 8 gas, Ar gas and a hydrogen-containing gas, etching the planarization layer under a contact mask to create a contact hole through which the second internal insulating film is exposed; wherein the hydrogen containing gas is C 2 H 2 gas that is added as an etching gas component so as to generate C--H type polymers that are weaker in bond strength but at a larger amount than C--C type polymers, so as to prevent an etching-stop phenomenon and underlying layer damage caused by over-etching during the etching step.
Claim 2
Independent Claim
170 words
A method for forming a hole of a semiconductor device, comprising: forming a word line and a first internal insulating film on a semiconductor substrate; forming an insulating film spacer at a side wall of the word line and the first insulating film so as to form a resulting structure; forming a nitride film as a second internal insulating film on the resulting structure; forming a planarization layer on the second internal insulating film; in an atmosphere including C 4 F 8 gas, Ar gas and a hydrogen-containing gas, etching the planarization layer under a contact mask to create a contact hole through which the second internal insulating film is exposed; wherein the hydrogen containing gas is C 2 H 2 gas that is added as an etching gas component so as to generate C--H type polymers that are weaker in bond strength but at a larger amount than C--C type polymers, so as to prevent an etching-stop phenomenon and underlying layer damage caused by over-etching during the etching step.
Claim 3
Dependent Claim
48 words
The method of claim 1, wherein the etching step is carried out: at a source power of 1000-3000 watts; at a bias power of 500-2000 watts; at a C 4 F 8 gas flow rate of 5-30 SCCM; and at an Ar gas flow rate of 0-500 SCCM.
Claim 4
Dependent Claim
21 words
The method of claim 2, wherein the etching step is carried out: at a hydrogen-containing gas flow rate of 0-30 SCCM.
Claim 5
Dependent Claim
21 words
The method of claim 1, wherein the etching step is carried out: at a hydrogen-containing gas flow rate of 0-30 SCCM.
Claim 6
Dependent Claim
33 words
The method of claim 1, wherein the etching step is carried out: at an etch ratio of the planarization layer to the second internal insulating film of a range from 50 to 200.
Claim 7
Independent Claim
185 words
A method for forming a hole of a semiconductor device, comprising: forming a word line and a first internal insulating film on a semiconductor substrate; forming an insulating film spacer at a side wall of the word line and the first insulating film so as to form a resulting structure; forming a nitride film as a second internal insulating film on the resulting structure; forming a planarization layer on the second internal insulating film; in an atmosphere including C 4 F 8 gas, Ar gas and a hydrogen-containing gas, etching the planarization layer under a contact mask to create a contact hole through which the second internal insulating film is exposed; wherein the hydrogen containing gas is selected from C 2 H 2 gas, CH 3 F gas, CH 2 F 2 gas, and CHF 3 gas, and is added as an etching gas component so as to generate C--H type polymers that are weaker in bond strength but at a larger amount than C--C type polymers, so as to prevent an etching-stop phenomenon and underlying layer damage caused by over-etching during the etching step.
Claim 8
Independent Claim
185 words
A method for forming a hole of a semiconductor device, comprising: forming a word line and a first internal insulating film on a semiconductor substrate; forming an insulating film spacer at a side wall of the word line and the first insulating film so as to form a resulting structure; forming a nitride film as a second internal insulating film on the resulting structure; forming a planarization layer on the second internal insulating film; in an atmosphere including C 4 F 8 gas, Ar gas and a hydrogen-containing gas, etching the planarization layer under a contact mask to create a contact hole through which the second internal insulating film is exposed; wherein the hydrogen containing gas is selected from C 2 H 2 gas, CH 3 F gas, CH 2 F 2 gas, and CHF 3 gas, and is added as an etching gas component so as to generate C--H type polymers that are weaker in bond strength but at a larger amount than C--C type polymers, so as to prevent an etching-stop phenomenon and underlying layer damage caused by over-etching during the etching step.
References Cited (Backward Citations)
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