US3346428A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making semiconductor devices by double diffusion
Assignee: Panasonic Holdings Corp
•
Filing: 1965-02-15
•
Granted: 1967-10-10
•
Expires: 1985-02-15
Abstract
No abstract record available.
Inventors
- 👤 Teramoto Iwao
- 👤 Iwasa Hitoo
- 👤 Shinoda Shosuke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:11
CPC Classifications
C; C30; C30B; C30B31/00; C30B31/02; H; H10; H10P; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/049; Y10S148/118; Y10S148/151
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
A METHOD OF PRODUCING A SEMICONDUCTOR DEVICE COMPRISING APPLYING A PHOSPHATE GLASS ON ONE FACE OF A SILICON WAFER, APPLYING BORON TRIOXIDE, B2O3, ON THE OTHER FACE OF THE SILICON WAFER AND HEATING THE COATED SILICON WAFER AT A TEMPERATURE OF 1100* TO 1300*C. TO DIFFUSE PHOSPHORUS AND BORON SIMULTANEOUSLY INTO THE RESPECTIVE SIDES OF THE SILICON WAFER; THE PHOSPHATE GLASS HAVING A VISCOSITY OF NOT MORE THAN 100 POISES AT A TEMPERATURE OF 1000*C., AND COMPRISING AT LEAST ONE ALKALI METAL OXIDE SELECTED FROM LITHUM OXIDE, SODIUM OXIDE AND POTASSIUM OXIDE; AT LEAST ONE ALKALI EARTH METAL OXIDE SELECTED FROM MAGNESIUM OXIDE, CALCIUM OXIDE, STRONTIUM OXIDE AND BARIUM OXIDE; AND PHOSPHORUS PENTOXIDE EXCEEDING IN MOL PERCENTAGE THE SUM OF THE MOL PERCENTAGES OF THE SELECTED ALKALI AND ALKALI EARTH METAL OXIDES.
Claim 2
Independent Claim
132 words
A METHOD OF PRODUCING A SEMICONDUCTOR DEVICE COMPRISING APPLYING A PHOSPHATE GLASS ON ONE FACE OF A SILICON WAFER, APPLYING BORON TRIOXIDE, B2O3, ON THE OTHER FACE OF THE SILICON WAFER AND HEATING THE COATED SILICON WAFER AT A TEMPERATURE OF 1100* TO 1300*C. TO DIFFUSE PHOSPHORUS AND BORON SIMULTANEOUSLY INTO THE RESPECTIVE SIDES OF THE SILICON WAFER; THE PHOSPHATE GLASS HAVING A VISCOSITY OF NOT MORE THAN 100 POISES AT A TEMPERATURE OF 1000*C., AND COMPRISING AT LEAST ONE ALKALI METAL OXIDE SELECTED FROM LITHUM OXIDE, SODIUM OXIDE AND POTASSIUM OXIDE; AT LEAST ONE ALKALI EARTH METAL OXIDE SELECTED FROM MAGNESIUM OXIDE, CALCIUM OXIDE, STRONTIUM OXIDE AND BARIUM OXIDE; AND PHOSPHORUS PENTOXIDE EXCEEDING IN MOL PERCENTAGE THE SUM OF THE MOL PERCENTAGES OF THE SELECTED ALKALI AND ALKALI EARTH METAL OXIDES.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-10-09 | 1971-04-10 | 1971-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-10-09 | 1975-04-10 | 1975-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-10-09 | 1979-04-10 | 1979-10-10 | $7700.00 | Window Closed / Lapsed |