US3149395A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a varactor diode by epitaxial growth and diffusion
Assignee: AT&T Inc
•
Filing: 1960-09-20
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Granted: 1964-09-22
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Expires: 1980-09-20
Abstract
No abstract record available.
Inventors
- 👤 Anthony R Bray
- 👤 Kahng Dawon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:39
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/62; H10D1/64; C; C30; C30B; C30B31/00; C30B31/02; H10D62/00; H10D62/10; H10D62/60; H10D99/00; H10F; H10F71/00; H10P; H10P32/00; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/007; Y10S148/037; Y10S148/115; Y10S148/151; Y10S438/00; Y10S438/914; Y10S438/916
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
130 words
THE PROCESS OF FABRICATING A VARACTOR DIODE COMPRISING THE STEPS OF FORMING ON A SURFACE PORTION OF A SEMICONDUCTIVE WAFER A DIFFUSANT-RICH LAYER, THE DIFFUSANT HAVING A CONDUCTIVITY-TYPE DETERMINING CHARACTERISTIC OPPOSITE THAT OF THE DOPING IMPURITY PREDOMINANT IN THE ADJACENT PORTION OF THE WAFER, THE DIFFUSANT HAVING A DIFFUSION CONSTANT LARGER THANT THAT OF SAID DOPING IMPURITY AND THE CONCENTRATION OF SAI DIFFUSANT IN SAID LAYER BEING LOWER THAN THAT OF SAID DOPING IMPURITY IN SAID ADJACENT PORTION, GROWING A HIGH RESISTIVITY EPITAXIAL FILM OVER SAID DIFFUSANT-RICH SURFACE PORTION, THE DIFFUSANT DIFFUSING FURTHER INTO SAID FILM THAN SAID DOPANT WHEREBY THERE IS FORMED IN THE EPITAXIAL FILM A RETROGRADED JUNCTION CHARACTERIZED BY A SHARPLY DECREASING CONCENTRATION OF THE DIFFUSANT WITH INCREASING DISTANCE AWAY FROM THE JUNCTION INTO THE EPITAXIAL FILM.
Claim 2
Dependent Claim
130 words
THE PROCESS OF FABRICATING A VARACTOR DIODE COMPRISING THE STEPS OF FORMING ON A SURFACE PORTION OF A SEMICONDUCTIVE WAFER A DIFFUSANT-RICH LAYER, THE DIFFUSANT HAVING A CONDUCTIVITY-TYPE DETERMINING CHARACTERISTIC OPPOSITE THAT OF THE DOPING IMPURITY PREDOMINANT IN THE ADJACENT PORTION OF THE WAFER, THE DIFFUSANT HAVING A DIFFUSION CONSTANT LARGER THANT THAT OF SAID DOPING IMPURITY AND THE CONCENTRATION OF SAI DIFFUSANT IN SAID LAYER BEING LOWER THAN THAT OF SAID DOPING IMPURITY IN SAID ADJACENT PORTION, GROWING A HIGH RESISTIVITY EPITAXIAL FILM OVER SAID DIFFUSANT-RICH SURFACE PORTION, THE DIFFUSANT DIFFUSING FURTHER INTO SAID FILM THAN SAID DOPANT WHEREBY THERE IS FORMED IN THE EPITAXIAL FILM A RETROGRADED JUNCTION CHARACTERIZED BY A SHARPLY DECREASING CONCENTRATION OF THE DIFFUSANT WITH INCREASING DISTANCE AWAY FROM THE JUNCTION INTO THE EPITAXIAL FILM.
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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) | 1967-09-22 | 1968-03-23 | 1968-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-09-22 | 1972-03-23 | 1972-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-09-22 | 1976-03-23 | 1976-09-22 | $7700.00 | Window Closed / Lapsed |