US4190466A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making a bipolar transistor structure utilizing self-passivating diffusion sources
Assignee: International Business Machines Corp
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Filing: 1977-12-22
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Granted: 1980-02-26
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Expires: 1997-12-22
Abstract
Abstract A semiconductor structure, formed within a recessed oxide isolation region, includes a semiconductor substrate of a first conductivity type within which a collector of opposite conductivity type is formed below the surface of the substrate and extending in part to the surface of the substrate for ease of contact. A first layer of doped polycrystalline silicon or polysilicon is formed on a first portion of the surface of the substrate and in electrical contact with the substrate which acts as the base of a transistor. The first polysilicon layer is oxidized to form an outer insulating layer thereover. A second doped polysilicon layer is disposed over the outer insulating layer onto a second portion of the surface of the substrate so as to be spaced from the first portion by only the thickness of the outer insulating layer on the first polysilicon layer. The dopant in the second polysilicon layer is driven into the surface of the semiconductor substrate to form an emitter therein. Means, which may include a portion of the second polysilicon layer, are provided for electrically contacting the collector to thus form a completed compact bipolar transistor which has very high performance.
Inventors
- 👤 Arup Bhattacharyya
- 👤 Francis W. Wiedman, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:27
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/21; G11C11/34; G11C11/40; G11C11/401; G11C11/403; G11C11/404; H; H10; H10B; H10B12/00; H10B12/10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0113; H10D84/00; H10D84/01; H10D84/0112; H10D84/02; H10D84/03; H10D84/038; H10D84/60; H10D84/611; H10D84/613; H10D84/615; H10P; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/1414; H10P32/17; H10P32/171; Y; Y10; Y10S; Y10S148/00; Y10S148/116; Y10S148/131
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
199 words
A method of making a transistor structure in a semiconductor substrate of a given conductivity type having a major surface comprising the steps of: isolating a region of said semiconductor substrate at said major surface, forming a collector region of a conductivity type opposite to that of said given conductivity type below and spaced from said major surface so as to define a base region between said collector region and said major surface, applying a first self-passivating conductive layer to a first portion of said major surface, passing impurities of said given conductivity type to said first portion of said major surface through said first self-passivating conductive layer to form a contact region in said base region, forming an insulating layer on the outer surface of said self-passivating conductive layer, applying a second conductive layer to said insulating layer and to a second portion of said major surface adjacent to said first surface portion, and passing impurities of said opposite conductivity type through said second conductive layer to said second surface portion adjacent said first surface portion to form within said base region an emitter region spaced within the thickness of said insulating layer from said first surface portion.
Claim 2
Independent Claim
199 words
A method of making a transistor structure in a semiconductor substrate of a given conductivity type having a major surface comprising the steps of: isolating a region of said semiconductor substrate at said major surface, forming a collector region of a conductivity type opposite to that of said given conductivity type below and spaced from said major surface so as to define a base region between said collector region and said major surface, applying a first self-passivating conductive layer to a first portion of said major surface, passing impurities of said given conductivity type to said first portion of said major surface through said first self-passivating conductive layer to form a contact region in said base region, forming an insulating layer on the outer surface of said self-passivating conductive layer, applying a second conductive layer to said insulating layer and to a second portion of said major surface adjacent to said first surface portion, and passing impurities of said opposite conductivity type through said second conductive layer to said second surface portion adjacent said first surface portion to form within said base region an emitter region spaced within the thickness of said insulating layer from said first surface portion.
Claim 3
Dependent Claim
34 words
A method of making a transistor structure as set forth in claim 1 wherein said collector region is formed by implanting ions into said isolated region at increasing depths beginning from said major surface.
Claim 4
Dependent Claim
44 words
A method of making a transistor structure as set forth in claim 2 wherein ions are implanted across the entire isolated region of said semiconductor substrate through material disposed on said major surface providing various degrees of resistance to the flow of said ions.
Claim 5
Dependent Claim
23 words
A method of making a transistor structure as set forth in claim 3 wherein said ions are implanted through a plurality of materials.
Claim 6
Dependent Claim
28 words
A method of making a transistor structure as set forth in claim 4 wherein said ions are implanted through a plurality of materials including a layer of photoresist.
Claim 7
Dependent Claim
32 words
A method of making a transistor structure as set forth in claim 1 wherein said first self-passivating conductive layer applied to the first portion of said major surface is made of polysilicon.
Claim 8
Dependent Claim
36 words
A method of making a transistor structure as set forth in claim 1 wherein the first self-passivating conductive layer applied to said first portion of said major surface is made of aluminum, tantalum, zirconium or niobium.
Claim 9
Dependent Claim
34 words
A method of making a transistor structure as set forth in claim 1 wherein said first self-passivating conductive layer applied to the first portion of said major surface is made of a metallic silicide.
Claim 10
Dependent Claim
33 words
A method of making a transistor structure as set forth in claim 6 wherein said second conductive layer applied to said insulating layer and to said second portion is a self-passivating conductive layer.
Claim 11
Dependent Claim
32 words
A method of making a transistor structure as set forth in claim 9 wherein said second self-passivating layer applied to said insulating layer and to said second portion is made of polysilicon.
Claim 12
Dependent Claim
27 words
A method of making a transistor structure as set forth in claim 6 wherein said insulating layer formed on said polysilicon layer is a polysilicon oxide layer.
Claim 13
Dependent Claim
89 words
A method of making a transistor structure as set forth in claim 1 wherein said first self-passivating conductive layer is applied to said first portion of said major surface by: applying an insulating medium to said isolated major surface of said semiconductor substrate, applying a photoresist layer over said insulating medium, etching an opening through said photoresist layer and said insulating medium to define said first portion of said major surface, and applying said first self-passivating conductive layer to said first portion of said major surface through said opening.
Claim 14
Dependent Claim
43 words
A method of making a transistor structure as set forth in claim 12 further including the steps of removing the remaining portion of said photoresist layer and then forming said insulating layer by oxidizing the outer surface of said first self-passivating conductive layer.
Claim 15
Dependent Claim
32 words
A method of making a transistor structure as set forth in claim 13 wherein said first self-passivating conductive layer applied to the first portion of said major surface is made of polysilicon.
Claim 16
Dependent Claim
51 words
A method of making a transistor structure as set forth in claim 14 wherein the remainder of said insulating medium is removed from said isolated major surface of said semiconductor substrate and then said second conductive layer is applied over said insulating layer and said second protion of said major surface.
Claim 17
Dependent Claim
35 words
A method of making a transistor structure as set forth in claim 15 wherein said second conductive layer applied over said insulating layer and said second portion of said major surface is made of polysilicon.
Claim 18
Dependent Claim
37 words
A method of making a transistor structure as set forth in claim 16 further including the steps of: forming a dielectric layer over said second conductive layer, and applying a third conductive layer over said dielectric layer.
Claim 19
Dependent Claim
33 words
A method of making a transistor structure as set forth in claim 17 further including the step of providing electrical connections to said first and third conductive layers and to said collector region.
Claim 20
Independent Claim
238 words
A method of making a transistor structure in a semiconductor substrate of a given conductivity type having a major surface comprising the steps of: isolating a region of said semiconductor substrate at said major surface, forming a collector region of a conductivity type opposite to that of said given conductivity type below and spaced from said major surface so as to define a base region between said collector region and said major surface, applying a first self-passivating conductive layer to a plurality of selected first portions of said major surface, passing impurities of said given conductivity type to said plurality of selected first portions of said major surface through said first self-passivating conductive layer to form a contact region in said base region, forming an insulating layer on the outer surface of said self-passivating conductive layer, applying a like plurality of segments of a second conductive layer to said insulating layer and to a like plurality of selected second portions of said major surface, each of said selected second portions being adjacent to one of said selected first portions of said major surface, and passing impurities of said opposite conductivity type through said plurality of segments of said second conductive layer to said plurality of selected second portions of said major surface to form within said base region a like plurality of emitters, each being spaced within the thickness of said insulating layer from said first surface portions.
Claim 21
Independent Claim
238 words
A method of making a transistor structure in a semiconductor substrate of a given conductivity type having a major surface comprising the steps of: isolating a region of said semiconductor substrate at said major surface, forming a collector region of a conductivity type opposite to that of said given conductivity type below and spaced from said major surface so as to define a base region between said collector region and said major surface, applying a first self-passivating conductive layer to a plurality of selected first portions of said major surface, passing impurities of said given conductivity type to said plurality of selected first portions of said major surface through said first self-passivating conductive layer to form a contact region in said base region, forming an insulating layer on the outer surface of said self-passivating conductive layer, applying a like plurality of segments of a second conductive layer to said insulating layer and to a like plurality of selected second portions of said major surface, each of said selected second portions being adjacent to one of said selected first portions of said major surface, and passing impurities of said opposite conductivity type through said plurality of segments of said second conductive layer to said plurality of selected second portions of said major surface to form within said base region a like plurality of emitters, each being spaced within the thickness of said insulating layer from said first surface portions.
Claim 22
Dependent Claim
41 words
A method of making a transistor structure as set forth in claim 19 wherein said first self-passivating conductive layer applied to said major surface is made of polysilicon and said plurality of selected first portions of said major surface are interconnected.
Claim 23
Dependent Claim
29 words
A method of making a transistor structure as set forth in claim 19 wherein said first self-passivating conductive layer applied to said major surface is made of anodizable material.
Claim 24
Dependent Claim
30 words
A method of making a transistor structure as set forth in claim 19 wherein said first self-passivating conductive layer applied to said major surface is made of a metallic silicide.
Claim 25
Dependent Claim
40 words
A method of making a transistor structure as set forth in claim 20 wherein said second conductive layer applied to said insulating layer and to said plurality of selected second portions of said major surface is a self-passivating conductive layer.
Claim 26
Dependent Claim
39 words
A method of making a transistor structure as set forth in claim 23 wherein said second self-passivating layer applied to said insulating layer and to said plurality of selected second portions of said major surface is made of polysilicon.
Claim 27
Dependent Claim
27 words
A method of making a transistor structure as set forth in claim 20 wherein said insulating layer formed on said polysilicon layer is a polysilicon oxide layer.
Claim 28
Dependent Claim
73 words
A method of making a transistor structure as set forth in claim 25 further including the steps of: forming a dielectric layer over each of said plurality of segments of said second conductive layer, and applying a like plurality of segments of a third conductive layer over said dielectric layer in juxtaposition with respect to said plurality of segments of said second conductive layer, whereby a like plurality of capacitors are formed thereby.
Claim 29
Dependent Claim
40 words
A method of making a transistor structure as set forth in claim 26 further including the step of providing electrical connections to said first conductive layer, said plurality of segments of said third conductive layer and to said collector region.
Claim 30
Dependent Claim
33 words
A method of making a transistor structure as set forth in claim 19 wherein said insulating layer is formed by converting the outer portion of said self-passivating conductive layer into an insulating material.
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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) | 1983-02-25 | 1983-08-27 | 1984-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-25 | 1987-08-27 | 1988-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-25 | 1991-08-27 | 1992-02-26 | $7700.00 | Window Closed / Lapsed |