US3880682A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of simultaneous double diffusion
Assignee: Siemens AG
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Filing: 1973-06-20
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Granted: 1975-04-29
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Expires: 1993-06-20
Abstract
Abstract The oxide layer is produced by thermal oxidation of the silicon surface using a processing gas comprising oxygen and an oxide of the dopant. This insures that during the production of the oxide layer no dopant penetrates into the semiconductor. Diffusion is carried out by a subsequently executed thermal process.
Inventors
- 👤 Wolfgang Muller
- 👤 Joachim Dathe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:37
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/141; C; C30; C30B; C30B31/00; C30B31/02; H10P32/12; H10P32/17; H10P32/171; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/053; Y10S148/078; Y10S148/118
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
159 words
A PROCESS OF DOPING A SILICON CRYSTAL BY INDIFFUSION, WHICH COMPRISES PRODUCING EPITAXIALLY A LAYER OF ONE CONDUCTANCE TYPE ON A WAFER SHAPED SILICON MONOCRYSTAL OF ANOTHER CONDUCTANCE TYPE, COATING SAID EPITAXIAL LAYER WITH A LAYER OF SIO2, ETCHING AT LEAST TWO WINDOWS THROUGH THE SIO2 LAYER WHICH OPEN ONTO THE EPITAZIAL LAYER, PRODUCING AN SIO2 DOPING LAYER, CONTAINING BORON OR PHOSPHORUS AS DOPANT, USING PURE OXYGEN AS OXIDATION MEANS WITH NEITHER THE BORON NOR PHOSPHORUS INDIFFUSING INTO THE UNDERLYING SILICON, COVERING THE DOPANT CONTAINING LAYER IN AT LEAST ONE WINDOW WITH A PYROLYTICALLY PRODUCED SIO2 LAYER, OPENING AT LEAST ONE WINDOW TO THE UNDERLYING SEMICONDUCTOR SURFACE, WHILE THE DOPANT CONTAINING SIO2 LAYER REMAINS AT LEAST IN ANOTHER WINDOW, AND BRINGING A DOPANT SUBSTANCE OF OPPOSITE TYPE FROM THE GAS PHASE THROUGH THE OPENED WINDOW, AND HEATING THE DOPED DEVICE SO THAT INDIFFUSION ALSO TAKES PLACE FROM THE DOPANT CONTAINING SIO2 LAYER COVERED WINDOWS INTO THE UNDERLYING EPITAXIAL LAYER.
Claim 2
Dependent Claim
159 words
A PROCESS OF DOPING A SILICON CRYSTAL BY INDIFFUSION, WHICH COMPRISES PRODUCING EPITAXIALLY A LAYER OF ONE CONDUCTANCE TYPE ON A WAFER SHAPED SILICON MONOCRYSTAL OF ANOTHER CONDUCTANCE TYPE, COATING SAID EPITAXIAL LAYER WITH A LAYER OF SIO2, ETCHING AT LEAST TWO WINDOWS THROUGH THE SIO2 LAYER WHICH OPEN ONTO THE EPITAZIAL LAYER, PRODUCING AN SIO2 DOPING LAYER, CONTAINING BORON OR PHOSPHORUS AS DOPANT, USING PURE OXYGEN AS OXIDATION MEANS WITH NEITHER THE BORON NOR PHOSPHORUS INDIFFUSING INTO THE UNDERLYING SILICON, COVERING THE DOPANT CONTAINING LAYER IN AT LEAST ONE WINDOW WITH A PYROLYTICALLY PRODUCED SIO2 LAYER, OPENING AT LEAST ONE WINDOW TO THE UNDERLYING SEMICONDUCTOR SURFACE, WHILE THE DOPANT CONTAINING SIO2 LAYER REMAINS AT LEAST IN ANOTHER WINDOW, AND BRINGING A DOPANT SUBSTANCE OF OPPOSITE TYPE FROM THE GAS PHASE THROUGH THE OPENED WINDOW, AND HEATING THE DOPED DEVICE SO THAT INDIFFUSION ALSO TAKES PLACE FROM THE DOPANT CONTAINING SIO2 LAYER COVERED WINDOWS INTO THE UNDERLYING EPITAXIAL LAYER.
References Cited (Backward Citations)
US3066052A
Cited
US3575742A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |