Patent US3926694A successfully refreshed from Google Patents.
US3926694A
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Double diffused metal oxide semiconductor structure with isolated source and drain and method
Assignee: Signetics Corp
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Filing: 1973-05-14
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Granted: 1975-12-16
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Expires: 1993-05-14
Abstract
Abstract Metal oxide semiconductor structure having precisely grown channel with the source and drain isolated from each other by a PN junction. In the method, a double diffusion is carried out through the same opening in an oxide or insulating layer to obtain a very narrow precise channel region with minimum spreading and which can be utilized with a P-type substrate to provide PN isolation between the source and drain.
Inventors
- 👤 Thomas P Cauge
- 👤 Joseph Kocsis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:57
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/64; H10D30/65; H10D30/01; H10D30/021; H10D30/028; H10D30/0281; H10D84/00; H10D84/80; H10D84/82; H10D84/83; H10P; H10P95/00; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/514; H10D64/516; Y; Y10; Y10S; Y10S148/00; Y10S148/053; Y10S148/085; Y10S148/167
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
199 words
IN A METHOD FOR FORMING A METAL INSULATOR SEMICONDUCTOR STRUCTURE, PROVIDING A SEMICONDUCTOR BODY HAVING AT LEAST A PORTION THEREOF WITH AN IMPURITY OF ONE CONDUCTIVITY TYPE, FORMING A LAYER OF SEMICONDUCTOR MATERIAL OF OPPOSITE CONDUCTIVITY TYPE ON SAID BODY TO FORM A FIRST PN JUCTION BETWEEN SAID BODY AND SAID LAYER OF SEMICONDUCTOR MATERIAL, SAID LAYER HAVING A SUBSTANTIALLY PLANAR SURFACE, FORMING A MASK ON SAID SURFACE OF THE SEMIOCONDUCTOR LAYER HAVING AN EDGE OVERLYING SAID SURFACE, DIFFUSING WITH AN IMPURITY OF SAID ONE CONDUCTIVITY TYPE THROUGH SAID SURFACE UTILIZING SAID MASK TO PROVIDE A FIRST REGION OF SAID ONE CONDUCTIVITY TYPE HAVING A DEPTH WHICH EXTENDS FROM SAID SURFACE THROUGH SAID LAYER OF SEMICONDUCTOR MATERIAL TO SAID SEMICONDUCTOR BODY AND BEING DEFINED BY A PN JUCTION WHICH EXTENDS FROM THE SURFACE BENEATH THE MASK THROUGH THE LAYER TO THE SEMICDONCUTR BODY, DIFFUSING WITH HEAT AN IMPURITY OF OPPOSITE CONDUCTIVITY TYPE THROUGH SAID SURFACE USING THE SAME EDGE OF THE MASK TO FORM A SECOND REGION IN SAID FIRST REGION WHICH IS OFFSET IN SAID FIRST REGION AND WITH A SURFACE AREA SUBSTANTIALLY LESS THAN THE SURFACE AREA OF SAID FIRST REGION AND WHICH IS DEFINED BY A
Claim 2
Dependent Claim
199 words
IN A METHOD FOR FORMING A METAL INSULATOR SEMICONDUCTOR STRUCTURE, PROVIDING A SEMICONDUCTOR BODY HAVING AT LEAST A PORTION THEREOF WITH AN IMPURITY OF ONE CONDUCTIVITY TYPE, FORMING A LAYER OF SEMICONDUCTOR MATERIAL OF OPPOSITE CONDUCTIVITY TYPE ON SAID BODY TO FORM A FIRST PN JUCTION BETWEEN SAID BODY AND SAID LAYER OF SEMICONDUCTOR MATERIAL, SAID LAYER HAVING A SUBSTANTIALLY PLANAR SURFACE, FORMING A MASK ON SAID SURFACE OF THE SEMIOCONDUCTOR LAYER HAVING AN EDGE OVERLYING SAID SURFACE, DIFFUSING WITH AN IMPURITY OF SAID ONE CONDUCTIVITY TYPE THROUGH SAID SURFACE UTILIZING SAID MASK TO PROVIDE A FIRST REGION OF SAID ONE CONDUCTIVITY TYPE HAVING A DEPTH WHICH EXTENDS FROM SAID SURFACE THROUGH SAID LAYER OF SEMICONDUCTOR MATERIAL TO SAID SEMICONDUCTOR BODY AND BEING DEFINED BY A PN JUCTION WHICH EXTENDS FROM THE SURFACE BENEATH THE MASK THROUGH THE LAYER TO THE SEMICDONCUTR BODY, DIFFUSING WITH HEAT AN IMPURITY OF OPPOSITE CONDUCTIVITY TYPE THROUGH SAID SURFACE USING THE SAME EDGE OF THE MASK TO FORM A SECOND REGION IN SAID FIRST REGION WHICH IS OFFSET IN SAID FIRST REGION AND WITH A SURFACE AREA SUBSTANTIALLY LESS THAN THE SURFACE AREA OF SAID FIRST REGION AND WHICH IS DEFINED BY A
Claim 3
Dependent Claim
97 words
A method as in claim 1 together with the step of forming an opening in said mask prior to the diffusion of said second region to form a window for the drain contact, depositing a sandwich of two layers of two different materials over said mask and in the opening in said mask, forming an opening in said sandwich sufficiently large enough to uncover the mask and the opening in the mask by selectively removing one of the materials in a predetermined area and thereafter selectively removing the other of the two materials in a predetermined area.
Claim 4
Dependent Claim
26 words
A method as in claim 2 wherein one of the two materials of the sandwich is silicon dioxide wherein said mask is formed of silicon dioxide.
Claim 5
Dependent Claim
16 words
A method as in claim 3 wherein the other of the two materials is silicon nitride.
Claim 6
Dependent Claim
20 words
A method as in claim 2 wherein said sandwich is removed after the diffusion of the source region is completed.
Claim 7
Dependent Claim
72 words
A method as in claim 1 together with the step of forming an opening in said mask prior to the diffusion of the second region, depositing a low temperature glass having an impurity of opposite conductivity type in the opening, on the mask and the areas adjacent the mask, removing undesired portions of the glass, and diffusing impurities from the glass into the layer of semiconductor material to form the second region.
Claim 8
Dependent Claim
190 words
In a method for forming a semiconductor structure having one and opposite conductivity type regions formed in a one conductivity body having a surface and a channel having a precise length between said regions and said body at said surface, the method comprising, providing a semiconductor body of one conductivity type having a substantially planar surface, forming a masking layer on said surface, removing a portion of said masking layer from said surface to provide a mask edge on said surface, diffusing a first region of opposite conductivity type extending downwardly from said surface into said body using said edge of said mask to define said first region, diffusing with heat an impurity of one conductivity type extending downwardly from said surface into said body within said first region to a depth substantially less than the depth of the first region using the same edge of said mask, said last named diffusion of said impurity of one conductivity type causing movement of said first named region beneath said mask, controlling the diffusion of the first and second regions to form a channel region at said surface having a precise length.
Claim 9
Dependent Claim
190 words
In a method for forming a semiconductor structure having one and opposite conductivity type regions formed in a one conductivity body having a surface and a channel having a precise length between said regions and said body at said surface, the method comprising, providing a semiconductor body of one conductivity type having a substantially planar surface, forming a masking layer on said surface, removing a portion of said masking layer from said surface to provide a mask edge on said surface, diffusing a first region of opposite conductivity type extending downwardly from said surface into said body using said edge of said mask to define said first region, diffusing with heat an impurity of one conductivity type extending downwardly from said surface into said body within said first region to a depth substantially less than the depth of the first region using the same edge of said mask, said last named diffusion of said impurity of one conductivity type causing movement of said first named region beneath said mask, controlling the diffusion of the first and second regions to form a channel region at said surface having a precise length.
Claim 10
Dependent Claim
126 words
A method as in claim 7 together with the additional steps prior to forming said second region at said mask edge of forming an opening in said mask spaced from said mask edge and exposing a portion of said body, forming a sandwich of two layers of two different materials over said mask and said exposed surface, forming an opening is said sandwich exposing a portion of said body adjacent said defined mask edge and in registry with the remaining mask edges by selectively removing one of the materials in a predetermined area and thereafter selectively removing the other of the two materials in a predetermined area, and utilizing said mask for forming the second region so that it is precisely spaced from the first region.
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) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |