Patent US3920482A successfully refreshed from Google Patents.
US3920482A
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Method for forming a semiconductor structure having islands isolated by adjacent moats
Assignee: Signetics Corp
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Filing: 1974-03-13
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Granted: 1975-11-18
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Expires: 1994-03-13
Abstract
Abstract Moat type isolation of semiconductor structures is provided by forming V-shaped grooves in an epitaxial layer formed on a semiconductor substrate and utilizing ion implantation to provide regions of higher impurity concentration at the apex of the groves to prevent field effect transistor or inversion action. In one method, the ion implantation is conducted before the epitaxial layer is grown. In another embodiment of the method, ion implantation is done after the epitaxial layer is formed by using the same mask window used for etching of the V-shaped groove.
Inventors
- 👤 Lewis K Russell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:18
CPC Classifications
H; H10; H10P; H10P95/00; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0145; H10W10/0148; H10W10/041; H10W10/10; H10W10/17; H10W10/40; Y; Y10; Y10S; Y10S148/00; Y10S148/049; Y10S148/051; Y10S148/085; Y10S148/115
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
144 words
A method for forming a semiconductor structure comprising the following steps: providing a silicon semiconductive substrate of one conductivity type and having a surface; forming an etch resistant mask on said surface of said substrate; causing by ion implantation through windows in said mask an impurity of said one conductivity type to be buried in said substrate having an impurity concentration greater than that of said substrate; epitaxially depositing on said surface a layer of silicon semiconductor material of an opposite conductivity type and having a top surface; forming an etch resistant mask on said top surface of said layer; forming by use of an etch and the mask a plurality of isolation moats extending downwardly from said top surface to intersect with said buried impurities; and forming an oxide layer on the walls of said moats to provide isolated islands of semiconductor material.
Claim 2
Independent Claim
144 words
A method for forming a semiconductor structure comprising the following steps: providing a silicon semiconductive substrate of one conductivity type and having a surface; forming an etch resistant mask on said surface of said substrate; causing by ion implantation through windows in said mask an impurity of said one conductivity type to be buried in said substrate having an impurity concentration greater than that of said substrate; epitaxially depositing on said surface a layer of silicon semiconductor material of an opposite conductivity type and having a top surface; forming an etch resistant mask on said top surface of said layer; forming by use of an etch and the mask a plurality of isolation moats extending downwardly from said top surface to intersect with said buried impurities; and forming an oxide layer on the walls of said moats to provide isolated islands of semiconductor material.
Claim 3
Dependent Claim
29 words
A method as in claim 1 where said moats are formed by an anisotropic etch to form V-shaped moats and the apex of the Vs intersect said buried impurities.
Claim 4
Dependent Claim
29 words
A METHOD AS IN CLAIM 1 WHERE SAID MOATS ARE FORMED BY AN ISOPROPIC ETCH TO FORM U-SHAPED MOATS AND THE BITES OF THE US INTERSECT SAID BURRIED IMPURITIES.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |