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US4226648A
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Method of making a hyperabrupt varactor diode utilizing molecular beam epitaxy
Assignee: AT&T Inc
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Filing: 1979-03-16
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Granted: 1980-10-07
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Expires: 1999-03-16
Abstract
Abstract A semiconductor varactor diode of the hyperabrupt junction type, typically having a PNN+ configuration, is disclosed. The impurity concentration in the intermediate N-type portion is grown in by the molecular beam epitaxy process to provide the hyperabrupt profile. Also, the N-type background doping in the P-type zone is minimized by the same epitaxial process to reduce the level of impurity compensation needed.
Inventors
- 👤 Charles A. Goodwin
- 👤 Yusuke Ota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:48
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/62; H10D1/64; H10P; H10P14/00; H10P14/20; H10P14/22; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/32; H10P14/3202; H10P14/3204; H10P14/3211; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; Y; Y10; Y10S; Y10S438/00; Y10S438/936
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
117 words
A method of fabricating a silicon semiconductor varactor diode of the hyperabrupt junction type in which an epitaxial layer having a PN junction therein is formed on a starting portion of high conductivity and of one conductivity type characterized by the steps of: (1) growing by molecular beam epitaxy on said starting portion a layer of one conductivity type and during said growing adding an impurity of said one conductivity type in an increasing amount so that the concentration of said impurity increases to a peak value, and (2) terminating the addition of said impurity to the growing process at the preselected peak value while continuing to grow said epitaxial layer thereby to form a surface-adjoining layer.
Claim 2
Independent Claim
117 words
A method of fabricating a silicon semiconductor varactor diode of the hyperabrupt junction type in which an epitaxial layer having a PN junction therein is formed on a starting portion of high conductivity and of one conductivity type characterized by the steps of: (1) growing by molecular beam epitaxy on said starting portion a layer of one conductivity type and during said growing adding an impurity of said one conductivity type in an increasing amount so that the concentration of said impurity increases to a peak value, and (2) terminating the addition of said impurity to the growing process at the preselected peak value while continuing to grow said epitaxial layer thereby to form a surface-adjoining layer.
Claim 3
Dependent Claim
25 words
The method in accordance with claim 1 in which an opposite type impurity is introduced into the surface-adjoining layer thereby to form a PN junction.
Claim 4
Dependent Claim
20 words
The method in accordance with claim 1 in which the impurity of said one conductivity type is antimony or arsenic.
Claim 5
Dependent Claim
27 words
The method in accordance with claim 1 in which said epitaxial growth occurs at temperatures in the range of from about 450° C. to about 950° C.
References Cited (Backward Citations)
US3201664A
Cited
US3208887A
Cited
US3312880A
Cited
US3411053A
Cited
US3383571A
Cited
US3483441A
Cited
US3638300A
Cited
US3634738A
Cited
US3764415A
Cited
US3860945A
Cited
US4106953A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-07 | 1984-04-07 | 1984-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-07 | 1988-04-07 | 1988-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-07 | 1992-04-07 | 1992-10-07 | $7700.00 | Window Closed / Lapsed |