US3993512A
Expired / Lapsed
US
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Method of manufacturing an integrated circuit utilizing outdiffusion and multiple layer epitaxy
Assignee: US Philips Corp
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Filing: 1974-12-19
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Granted: 1976-11-23
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Expires: 1994-12-19
Abstract
Abstract Method of producing integrated circuit including bipolar transistors, comprising the steps of forming collector zone of a first transistor at least partly by diffusing an impurity from a substrate part that is, before the growth of a first epitaxial layer on the substrate, doped at least locally with the impurity, forming the first epitaxial layer, and forming the collector zone of a second transistor by diffusing an impurity in the first epitaxial layer prior to growing a second epitaxial layer. Also, an integrated circuit produced by this method.
Inventors
- 👤 Jean Encinas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:00
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/60; H10D84/641; H10D84/642; H10W; H10W10/00; H10W10/01; H10W10/031; H10W10/30; Y; Y10; Y10S; Y10S148/00; Y10S148/037; Y10S148/085; Y10S148/145; Y10S148/151
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
266 words
A method of producing a semiconductor device comprising a plurality of transistors, comprising the steps of: a. providing a semiconductor substrate defining a first surface region; b. locally providing at a first portion of said first surface region a first conductivity type impurity to form a first doping region thereat; c. providing a first epitaxial layer at said first surface region above said first doping region, said first epitaxial layer having a second conductivity type opposite that of said first type, said first layer defining a second surface region; d. locally providing at a first portion of said second surface region a doping impurity material of said first conductivity type to form a second doping region thereat; said second doping region being laterally disposed with respect to said first doping region; e. providing a second epitaxial layer of said second conductivity type at the second surface region of said first layer above said second doping region, said second layer comprising a third surface region; f. diffusing said first conductivity type impurity material from said first and second doping regions into areas closer to the surface of said second epitaxial layer so as to form respective collector zones for first and second ones of said transistors, said first doping region extending further from the surface of said second epitaxial layer that said second doping region; and then g. forming at said diffused doping regions respective emitter and base zones for said transistors, said base zones having conductivity types opposite to those of said doping regions and said emitter zones having similar conductivity types to said doping regions.
Claim 2
Independent Claim
266 words
A method of producing a semiconductor device comprising a plurality of transistors, comprising the steps of: a. providing a semiconductor substrate defining a first surface region; b. locally providing at a first portion of said first surface region a first conductivity type impurity to form a first doping region thereat; c. providing a first epitaxial layer at said first surface region above said first doping region, said first epitaxial layer having a second conductivity type opposite that of said first type, said first layer defining a second surface region; d. locally providing at a first portion of said second surface region a doping impurity material of said first conductivity type to form a second doping region thereat; said second doping region being laterally disposed with respect to said first doping region; e. providing a second epitaxial layer of said second conductivity type at the second surface region of said first layer above said second doping region, said second layer comprising a third surface region; f. diffusing said first conductivity type impurity material from said first and second doping regions into areas closer to the surface of said second epitaxial layer so as to form respective collector zones for first and second ones of said transistors, said first doping region extending further from the surface of said second epitaxial layer that said second doping region; and then g. forming at said diffused doping regions respective emitter and base zones for said transistors, said base zones having conductivity types opposite to those of said doping regions and said emitter zones having similar conductivity types to said doping regions.
Claim 3
Dependent Claim
56 words
A method as recited in claim 1, wherein before said step of providing said first epitaxial layer, a further doping impurity material of said first conductivity type is locally provided at peripheral portions of said first doping region, said further doping impurity having a higher diffusion coefficient than said doping impurity comprising said first doping region.
Claim 4
Dependent Claim
121 words
A method as recited in claim 2, wherein before said step of diffusing said second conductivity type material from said first and second doping regions, a doping impurity material of said first conductivity type is provided at a first portion of said third surface region to form thereat a third doping region located above said peripheral portions of said first doping region and said step of diffusing said first conductivity type material from said first and second doping regions is carried out such that said further doping impurity material at said peripheral portions and said impurity material of said third doping region are diffused to each other so as to form a collector wall for said first one of said transistors.
Claim 5
Dependent Claim
33 words
A method as recited in claim 3, wherein said first transistor emitter zone is formed by diffusing a first conductivity type doping material into said second epitaxial layer from said third surface region.
Claim 6
Dependent Claim
113 words
A method as recited in claim 3, wherein before said step of diffusing said second conductivity type material from said first and second doping regions, a doping impurity material of said first conductivity type is provided at second portion of said third surface region to form a fourth doping region located directly above a portion of said first doping region located within said peripheral portions and said step of diffusing said first conductivity type material from said first and second doping regions is carried out such that said impurity material of said fourth doping region is diffused into at least said second epitaxial layer, thereby forming an emitter zone for said first transistor.
Claim 7
Dependent Claim
238 words
A method as recited in claim 3, comprising the further steps of: a. locally providing said first conductivity type doping impurity at a second portion of said first surface region removed from said first portion thereof to form a fifth doping region at said second portion, said fifth doping region being formed simultaneously with said step of forming said first doping region; b. providing said further doping impurity material of said second conductivity type locally at peripheral portions of said fifth doping region simultaneously with said provision of said further doping material at said peripheral portions of said first doping region; c. providing at a third portion of said third surface region a doping material of said second conductivity type to form sixth doping regions located above said peripheral portions of said fifth doping region, said sixth doping regions being formed simultaneously with said third doping regions; d. carrying out said step of diffusing said second conductivity type material from said first and second regions such that said impurity materials of said fifth and sixth doping regions are diffused to each other so as to form an isolation zone for a third transistor, said isolation zone comprising respective parts of said first and second epitaxial layers, said respective parts comprising the collector zone of said third transistors; e. forming the base and emitter zones of said third transistor in said respective parts of said first and second layers.
Claim 8
Dependent Claim
23 words
A method as recited in claim 6, wherein said third transistor isolation zone is formed simultaneously with said collector of said first transistor.
Claim 9
Dependent Claim
85 words
A method as recited in claim 6, wherein said base zone of said third transistor is formed by steps comprising forming locally at a second portion of said second surface region of said first epitaxial layer a seventh doping region of said second conductivity type doping material, said seventh region being located above said fifth doping region in said substrate and being formed before providing said second eptiaxial layer, said seventh region doping material being locally diffused completely through the thickness of said second layer.
Claim 10
Dependent Claim
24 words
A method as recited in claim 6, wherein said third transistor base zone is formed simultaneously with said collector zone of said second transistor.
Claim 11
Dependent Claim
42 words
A method as recited in claim 6, wherin an emitter region for said third transistor is formed by steps comprising locally diffusing said second conductivity type doping impurity into a fourth portion of said third surface region of said second epitaxial layer.
Claim 12
Dependent Claim
22 words
A method as recited in claim 10, wherein said third transistor emitter region is formed simultaneously with said second transistor base region.
Claim 13
Dependent Claim
67 words
A method as recited in claim 1, wherein the diffusion of said doping impurity material from said second doping region is carried out such that said doping material reaches said third surface region, thereby forming in said second layer a surface zone comprising a collector zone for said second transistor and then said base and emitter zones for said second transistor are formed within said surface zone.
Claim 14
Dependent Claim
52 words
A method as recited in claim 2, wherein said step of forming said base zone comprises diffusing a doping impurity material of said first conductivity type into a portion of said surface zone from said third surface region, thereby forming a second surface zone comprising the base zone of said second transistor.
Claim 15
Dependent Claim
43 words
A method as recited in claim 13, wherein said step of forming an emitter region comprises diffusing into a portion of said second surface zone a doping impurity material of said second conductivity type, thereby providing the emitter zone of said second transistor.
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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) | 1979-11-23 | 1980-05-24 | 1980-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-23 | 1984-05-24 | 1984-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-23 | 1988-05-24 | 1988-11-23 | $7700.00 | Window Closed / Lapsed |