US3573115A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealed tube diffusion process
Assignee: Infineon Technologies Americas Corp
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Filing: 1968-04-22
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Granted: 1971-03-30
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Expires: 1988-04-22
Abstract
Abstract A STACK OF SEMICONDUCTOR WAFERS IS PLACED IN A DIFFUSION BOAT WHICH IS LOADED INTO A QUARTZ TUBE. THE TUBE IS FILLED WITH A PREDETERMINED VOLUME OF GAS CONTAINING DOPING AGENTS ALONE, OR DOPING AGENTS AND OXYGEN, AND THE TUBE IS SEALED. THE TUBE IS THEN HEATED AT A RELATIVELY LOW TEMPERATURE IN A DIFFUSION CHAMBER TO CAUSE INITIAL DECOMPOSITION OF THE DOPING MATERIALS ON THE WAFERS, AND THEREAFTER AT A HIGHER TEMPERATURE TO CAUSE DIFFUSION OF THE DOPING MATERIALS INTO THE WAFER AS WELL AS OXIDATION OF THE WAFER SURFACE.
Inventors
- 👤 Benjamin Topas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:37
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/17; H10P32/171; H10D; H10D99/00; H10P32/14; H10P32/1404; Y; Y10; Y10S; Y10S148/00; Y10S148/051; Y10S148/085; Y10S438/00; Y10S438/914; Y10S438/92
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-29 | 1974-09-28 | 1975-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-29 | 1978-09-28 | 1979-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-29 | 1982-09-28 | 1983-03-30 | $7700.00 | Window Closed / Lapsed |