US3840409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Insulating layer pedestal transistor device and process
Assignee: International Business Machines Corp
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Filing: 1972-05-08
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Granted: 1974-10-08
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Expires: 1992-05-08
Abstract
Abstract Structures and processes of making high frequency self isolating pedestal transistors in P layer and non-self isolating pedestal transistor in N layer by employing an insulating layer formed by ion implementation to separate extrinsic collector and base region.
Inventors
- 👤 K Ashar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:35
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/137; H10D62/138; H10D62/113; H10D62/115; H10D84/00; H10D84/60; H10D84/67; H10D84/673; H10D99/00; H10P; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/037; Y10S148/085; Y10S148/145
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
109 words
A method for fabricating a pedestal transistor in monolithic form comprising the steps of: a. providing a substrate; b. introducing an impurity into the substrate to form an extrinsic buried subcollector region; c. forming an epitaxial layer over the substrate; d. introducing an amorphous insulating layer into the epitaxial layer, the insulating layer being positioned over the extrinsic buried subcollector region; e. forming a base and emitter region; and f. treating the substrate and epitaxial layer so as to form a pedestal internal collector region by allowing the impurities in the subcollector region to extend upward into the expitaxial layer so as to define an internal pedestal collector region.
Claim 2
Independent Claim
109 words
A method for fabricating a pedestal transistor in monolithic form comprising the steps of: a. providing a substrate; b. introducing an impurity into the substrate to form an extrinsic buried subcollector region; c. forming an epitaxial layer over the substrate; d. introducing an amorphous insulating layer into the epitaxial layer, the insulating layer being positioned over the extrinsic buried subcollector region; e. forming a base and emitter region; and f. treating the substrate and epitaxial layer so as to form a pedestal internal collector region by allowing the impurities in the subcollector region to extend upward into the expitaxial layer so as to define an internal pedestal collector region.
Claim 3
Dependent Claim
28 words
A method for fabricating a pedestal transistor in monolithic form as in claim 1 wherein: a. the insulating layer is introduced into the epitaxial layer by ion implantation.
Claim 4
Dependent Claim
29 words
A method for fabricating a pedestal transistor in monolithic form as in claim 2 wherein: a. a base region is formed by introducing an impurity into the expitaxial region.
Claim 5
Dependent Claim
36 words
A method for forming a pedestal transistor in monolithic form comprising the steps of claim 2 and further including: a. controlling the formation of the epitaxial region so that a portion thereof constitutes a base region.
Claim 6
Dependent Claim
35 words
The method for fabricating a pedestal transistor as in claim 1 wherein said insulating layer positioned over the extrinsic buried sub-collector region including upwardly extending sidewalls that extend to the surface of the epitaxial layer.
Claim 7
Dependent Claim
33 words
The method for fabricating a pedestal transistor as in claim 5 wherein a second amorphous layer is introduced into the epitaxial layer, the layer being positioned beneath said buried sub-collector in said substrate.
Claim 8
Dependent Claim
29 words
The method for fabricating a pedestal transistor as in claim 6 wherein said second insulating layer including upwardly extending sidewalls that extend to the surface of the epitaxial layer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |