US3923569A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of etching a semiconductor element
Assignee: Panasonic Holdings Corp
•
Filing: 1973-05-17
•
Granted: 1975-12-02
•
Expires: 1993-05-17
Abstract
Abstract Gas etching method in which an etching gas generated through reaction of HC1 and HNO3 is applied onto a semiconductor substrate while maintaining the temperature of the substrate at a relatively low temperature above the boiling point of water. This etching method is particularly effective for the compound semiconductor such as GaP, GaAs, GaAsP and the like.
Inventors
- 👤 Takuhiro Ono
- 👤 Masafumi Hashimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:34
CPC Classifications
H; H10; H10P; H10P95/00; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0116; H10D99/00; H10P50/00; H10P50/20; H10P50/24; H10P50/246
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
50 words
A METHOD OF GAS-ETCHING, WHICH COMPRISES APPLYING AND ETCHING GAS COMPOSED OF NOCL AND CL2, WHICH IS GENERATED THROUGH THE REACTION OF HCL AND HNO3, ONTO A SEMICONDUCTOR SUBSTRATE WHILE MAINTAINING THE TEMPERATURE OF SAID SEMICONDFIG-01 DUCTOR SUBSTRATE AT A PREDETERMINED TEMPERATURE ABOVE THE BOILING POINT OF UP TO 400*C.
Claim 2
Independent Claim
50 words
A METHOD OF GAS-ETCHING, WHICH COMPRISES APPLYING AND ETCHING GAS COMPOSED OF NOCL AND CL2, WHICH IS GENERATED THROUGH THE REACTION OF HCL AND HNO3, ONTO A SEMICONDUCTOR SUBSTRATE WHILE MAINTAINING THE TEMPERATURE OF SAID SEMICONDFIG-01 DUCTOR SUBSTRATE AT A PREDETERMINED TEMPERATURE ABOVE THE BOILING POINT OF UP TO 400*C.
Claim 3
Dependent Claim
15 words
A method according to claim 1 wherein said predetermined temperature is 200* to 400* C.
Claim 4
Dependent Claim
19 words
A method according to claim 1, which further comprises regulating the ratio of water contained in said etching gas.
Claim 5
Dependent Claim
18 words
A method according to claim 1, which further comprises preheating said etching gas at 250* to 400* C.
Claim 6
Dependent Claim
28 words
A method according to claim 1, in which said etching gas is generated by dripping a mixture of HCl solution and HNO3 solution into a gas generating device.
Claim 7
Dependent Claim
19 words
A method according to claim 1, in which said etching gas is generated by mixing HCl and HNO3 gas.
Claim 8
Dependent Claim
20 words
A method according to claim 1, in which said etching gas is generated by passing HNO3 gas through HCl solution.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |