Patent US4979010A successfully refreshed from Google Patents.
US4979010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
VLSI self-aligned bipolar transistor
Assignee: Texas Instruments Inc
•
Filing: 1989-08-09
•
Granted: 1990-12-18
•
Expires: 2009-08-09
Abstract
Abstract A self-aligned bipolar transistor in which an emitter polysilicon layer is used to align both an extrinsic base region and a deep collector contact. The diffused extrinsic base is separated from the diffused emitter region by an oxide sidewall segment. Doping of the extrinsic base and the emitter is achieved by diffusion from doped overlying polysilicon loayers. The resultant structure is size limited primarily by the metal pitch of the leads.
Inventors
- 👤 Jeffrey E. Brighton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:23
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/051; H10D10/40; H10D10/441; Y; Y10; Y10S; Y10S257/00; Y10S257/90
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
212 words
A bipolar transistor formed on a transistor region of a semiconductor substrate of a first conductivity type, comprising: a bureid DUF collector on said substrate and an overlying epitaxial layer both of a second conductivity type; an isolation region around said transistor region; an intrinsic base region in said epitaxail layer of a first conductivity type; an insulating layer over said epitaxial layer having a base contact opening; a sidewall insulating plug on a sidewall of the insulating layer; an emitter region of the second conductivity type nested within said intrinsic base region and an overlying emitter polysilicon layer in contact therewith, the emitter polysilicon layer formed in the base contact opening for use as an emitter dopant source for an emitter region below said polysilicon, said sidewall insulating plug used to space the emitter polysilicon layer from an edge of said insulating layer so that an emitter diffusion from said emitter polysilicon into said intrinsic base region is nested within said intrinsic base region due to the spacing effect of the sidewall sidewall insulating plug; an extrinsic base region adjacent to said emitter region formed in alignment with said emitter polysilicon layer; and a collector contact region extending through said epitaxial layer to said DUF collector of the second conductivity type.
Claim 2
Dependent Claim
212 words
A bipolar transistor formed on a transistor region of a semiconductor substrate of a first conductivity type, comprising: a bureid DUF collector on said substrate and an overlying epitaxial layer both of a second conductivity type; an isolation region around said transistor region; an intrinsic base region in said epitaxail layer of a first conductivity type; an insulating layer over said epitaxial layer having a base contact opening; a sidewall insulating plug on a sidewall of the insulating layer; an emitter region of the second conductivity type nested within said intrinsic base region and an overlying emitter polysilicon layer in contact therewith, the emitter polysilicon layer formed in the base contact opening for use as an emitter dopant source for an emitter region below said polysilicon, said sidewall insulating plug used to space the emitter polysilicon layer from an edge of said insulating layer so that an emitter diffusion from said emitter polysilicon into said intrinsic base region is nested within said intrinsic base region due to the spacing effect of the sidewall sidewall insulating plug; an extrinsic base region adjacent to said emitter region formed in alignment with said emitter polysilicon layer; and a collector contact region extending through said epitaxial layer to said DUF collector of the second conductivity type.
Claim 3
Dependent Claim
21 words
A biplar transistor according to claim 1, including an insulating spacer plug on a first sidewall of said emitter polysilicon layer.
Claim 4
Dependent Claim
24 words
A bipolar transistor according to claim 2, including a base polysilicon layer contacting said extrinsic base region in abuttment with said insulating spacer plug.
Claim 5
Dependent Claim
27 words
A bipolar transistor according to claim 2, wherein said DUF collector impurity is antimony, said first conductivity type is P-type and said second conductivity type is N-type.
Claim 6
Dependent Claim
24 words
A bipolar transistor according to claim 3, including a silicide layer formed over said emitter and base polysilicon layers and said collector contact region.
Claim 7
Dependent Claim
23 words
A bipolar transistor according to claim 1, wherein said isolation region is a trench extending down through said epitaxial layer into said substrate.
Claim 8
Dependent Claim
23 words
A bipolar transistor according to claim 1, including an insulating extrinsic base spacer plug on a second sidewall of said emitter polysilicon layer.
Claim 9
Dependent Claim
32 words
A bipolar transistor according to claim 7, including an electrically conductive extrinsic base contact formed subsequent to said emitter polysilicon layer and spaced from the latter by said extrinsic base spacer plug.
Claim 10
Dependent Claim
27 words
A bipolar transistor according to claim 1 wherein said DUF collector impurity is antimony, said first conductivity type is P-type and said second conductivity type is N-type.
Claim 11
Dependent Claim
22 words
A bipolar transistor according to claim 8, including a silicide layer formed over said emitter polysilicon layer and said collector contact region.
Claim 12
Dependent Claim
23 words
A bipolar transistor according to claim 1, wherein said isolation region is a trench extending down through said epitaxial layer into said substrate.
Claim 13
Dependent Claim
135 words
A bipolar transistor formed on a transistor region of a semiconductor substrate of a first conductivity type, comprising: a buried DUF collector on said substrate and an overlying epitaxial layer both of a second conductivity type; an isolation region around said transistor region; an intrinsic base region in said epitaxial layer of a first conductivity type; an emitter region of the second conductivity type nested within said intrinsic base region and an overlying emitter polysilicon layer in contact therewith; an extrinsic base region adjacent to said emitter region formed in alignment with one edge of said emitter polysilicon layer; and a collector contact region extending through said epitaxial layer to said DUF collector of the second conductivity type, said collector contact region being formed in alignment with the opposite edge of said emitter polysilicon layer.
Claim 14
Dependent Claim
135 words
A bipolar transistor formed on a transistor region of a semiconductor substrate of a first conductivity type, comprising: a buried DUF collector on said substrate and an overlying epitaxial layer both of a second conductivity type; an isolation region around said transistor region; an intrinsic base region in said epitaxial layer of a first conductivity type; an emitter region of the second conductivity type nested within said intrinsic base region and an overlying emitter polysilicon layer in contact therewith; an extrinsic base region adjacent to said emitter region formed in alignment with one edge of said emitter polysilicon layer; and a collector contact region extending through said epitaxial layer to said DUF collector of the second conductivity type, said collector contact region being formed in alignment with the opposite edge of said emitter polysilicon layer.
References Cited (Backward Citations)
US3379584A
Cited
US4157269A
Cited
US4381953A
Cited
FR2508704A1
Cited
US4495512A
Cited
US4583106A
Cited
EP0166923A2
Cited
EP0168324A2
Cited
EP0170250A2
Cited
US4686763A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-17 | 1994-06-18 | 1994-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-17 | 1998-06-18 | 1998-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-17 | 2002-06-18 | 2002-12-18 | $7700.00 | Window Closed / Lapsed |