EP0514013A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for etching polysilicon film
Assignee: NEC Corp
•
Filing: 1992-04-16
•
Granted: —
•
Expires: 2012-04-16
Abstract
Abstract In etching a polysilicon film having a large step difference by means of the RIE method, use is made of a mixed gas of HBr and Ar (10 to 25 %) or a mixed gas of HBr, Ar (5 to 25 %), and O₂ (0.2 to 2 %). With this arrangement, it is possible to eliminate the residuals in the step part, and etch the polysilicon film with high anisotropy with little etching of the underlying oxide film.
Inventors
- 👤 Hirokazu c/o NEC Corporation Oikawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 22:57
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
68 words
A method for etching a polysilicon film formed via an insulating film on the surface of a semiconductor substrate which underwent an impurity diffusion process by a reactive ion etching method that carries out ion etching in a reaction chamber having the atmosphere of an etching gas of a predetermined total gas flow, characterized in that said etching gas contains at least hydrogen bromide (HBr) and argon (Ar).
Claim 2
Dependent Claim
38 words
An etching method for a polysilicon film as claimed in claim 1, wherein the ratio of gas flow of said argon is set to be in the range of 10 to 25 % of said total gas flow.
Claim 3
Independent Claim
67 words
A method for etching a polysilicon film formed via an insulating film on the surface of a semiconductor substrate which underwent an impurity diffusion process by a reactive ion etching method that carries out ion etching in a reaction chamber having the atmosphere of an etching gas of a predetermined total gas flow, characterized in that said etching gas contains at least hydrogen bromide, argon, and oxygen.
Claim 4
Dependent Claim
61 words
An etching method for a polysilicon film as claimed in claim 3, wherein the ratio of gas flow of said argon is set to be in the range of 5 to 25 % of said total gas flow and the ratio of said oxygen is set to be in the range of 0.2 to 2 % of said total gas flow.
Claim 5
Dependent Claim
24 words
An etching method for a polysilicon film as claimed in claim 1 or claim 3, characterized in that said etching gas contains herium (He).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.