Patent US4820378A successfully refreshed from Google Patents.
US4820378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for etching silicon nitride selectively to silicon oxide
Assignee: Texas Instruments Inc
•
Filing: 1987-07-17
•
Granted: 1989-04-11
•
Expires: 2007-07-17
Abstract
Abstract A process for etching silicon nitride which is selective to silicon oxide with a vacuum processing module which has a remote plasma, which is generated form a gas including He and SF 6 , introduced to the wafer face.
Inventors
- 👤 Lee M. Loewenstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:03
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
57 words
A process for etching silicon nitride on the face of a wafer with the face including silicon nitride and silicon oxide comprising the steps of: (a) disposing said wafer in a low pressure chamber; (b) introducing remote generated plasma produced from a gas including SF 6 and Helium at the face of said wafer at low pressure.
Claim 2
Dependent Claim
57 words
A process for etching silicon nitride on the face of a wafer with the face including silicon nitride and silicon oxide comprising the steps of: (a) disposing said wafer in a low pressure chamber; (b) introducing remote generated plasma produced from a gas including SF 6 and Helium at the face of said wafer at low pressure.
Claim 3
Dependent Claim
36 words
Process as set forth in claim 1 wherein said remote generated plasma is produced with Helium flowing at 5000 sccm, SF 6 flowing at 100 sccm and the wafer having a temperature of 25 degrees C.
Claim 4
Dependent Claim
16 words
Process as set forth in claim 1 wherein the face of said wafer is facing downward.
Claim 5
Dependent Claim
28 words
Process as set forth in claim 1 including the step of generating an in situ plasma near the face of said wafer simultaneously with the step of introducing.
Claim 6
Dependent Claim
73 words
A process for etching face of a wafer with the face including silicon nitride and silicon oxide comprising the steps of: (a) disposing the wafer in a process chamber; (b) generating an etchant from a gas in a plasma generator remote from the process chamber said etchant being capable of etching silicon nitride at a greater rate than it etches silicon dioxide; and (c) introducing said etchant to the face of the wafer.
Claim 7
Dependent Claim
73 words
A process for etching face of a wafer with the face including silicon nitride and silicon oxide comprising the steps of: (a) disposing the wafer in a process chamber; (b) generating an etchant from a gas in a plasma generator remote from the process chamber said etchant being capable of etching silicon nitride at a greater rate than it etches silicon dioxide; and (c) introducing said etchant to the face of the wafer.
Claim 8
Dependent Claim
16 words
The process as set forth in claim 5 wherein the gas is a fluorine containing gas.
Claim 9
Dependent Claim
15 words
The process as set forth in claim 5 wherein the gas is SF 6 .
Claim 10
Dependent Claim
13 words
The process as set forth in claim 5 wherein the gas includes helium.
Claim 11
Dependent Claim
24 words
The process as set forth in claim 5 wherein the gas is helium flowing at 5000 sccm and SF 6 flowing at 100 sccm.
Claim 12
Dependent Claim
34 words
The process as set forth in claim 5 wherein the gas is helium flowing at 5000 sccm and SF 6 flowing at 100 sccm and the wafer has a temperature of 25 degrees C.
Claim 13
Dependent Claim
20 words
The process as set forth in claim 5 wherein the face of the wafer to be processed is facing downward.
Claim 14
Dependent Claim
29 words
The process as set forth in claim 5 including the step of generating an in situ plasma near the face of said wafer simultaneously with the step of introducing.
References Cited (Backward Citations)
JPS57167631A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-10 | 2000-10-10 | 2001-04-11 | $7700.00 | Window Closed / Lapsed |