US5616508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High speed bipolar transistor using a patterned etch stop and diffusion source
Assignee: Texas Instruments Inc
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Filing: 1995-01-09
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Granted: 1997-04-01
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Expires: 2015-01-09
Abstract
Abstract A bipolar transistor (100) and a method for forming the same. A base-link diffusion source layer (118) is formed over a portion of the collector region (102). The base-link diffusion source layer (118) comprises a material that is capable of being used as a dopant source and is capable of being etched selectively with respect to silicon. A base electrode (114) is formed over at least one end portion of the base-link diffusion source layer (118) and the exposed portions of the base-link diffusion source layer (118) are removed. An extrinsic base region (110) is diffused from the base electrode (114) and a base link-up region (112) is diffused from the base-link diffusion source layer (118). Processing may then continue to form an intrinsic base region (108), emitter region (126), and emitter electrode (124).
Inventors
- 👤 F. Scott Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:40
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/051; H10D10/40; H10D10/421
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
105 words
A method for forming a bipolar transistor, comprising the steps of: forming a collector region; forming a base-link diffusion source layer over a portion of said collector region; forming a base electrode overlying at least one end portion of said base-link diffusion source layer; removing said base-link diffusion source layer except for said at least one end portion; diffusing an extrinsic base region from said base electrode and a base link-up region from said at least one end portion of said base link layer; and implanting an intrinsic base region into said portion of said collector region except for said at least one end portion.
Claim 2
Independent Claim
105 words
A method for forming a bipolar transistor, comprising the steps of: forming a collector region; forming a base-link diffusion source layer over a portion of said collector region; forming a base electrode overlying at least one end portion of said base-link diffusion source layer; removing said base-link diffusion source layer except for said at least one end portion; diffusing an extrinsic base region from said base electrode and a base link-up region from said at least one end portion of said base link layer; and implanting an intrinsic base region into said portion of said collector region except for said at least one end portion.
Claim 3
Dependent Claim
15 words
The method of claim 1, wherein said base-link diffusion source layer comprises a silicate glass.
Claim 4
Dependent Claim
14 words
The method of claim 1, wherein said base-link diffusion source layer comprises borosilicate glass.
Claim 5
Dependent Claim
15 words
The method of claim 1, wherein said base-link diffusion source layer comprises a phosphosilicate glass.
Claim 6
Dependent Claim
13 words
The method of claim 1, wherein said base-link diffusion source layer comprises silicon-germanium.
Claim 7
Dependent Claim
55 words
The method of claim 1, wherein the step of forming said base electrode comprises the steps of: depositing a first layer of polysilicon over said collector region and said base-link diffusion source layer; and etching said first layer of polysilicon to form said base electrode, wherein said base-link diffusion source layer acts as an etchstop.
Claim 8
Dependent Claim
50 words
The method of claim 6, further comprising the steps of: forming a dielectric layer over said first layer of polysilicon; and etching said dielectric layer to remove a portion of said dielectric layer over said base-link diffusion source layer prior to said step of etching said first layer of polysilicon.
Claim 9
Dependent Claim
29 words
The method of claim 1, further comprising the steps of: forming an emitter electrode over said intrinsic base region; and forming an emitter region within said intrinsic base region.
Claim 10
Independent Claim
149 words
A method for forming a double polysilicon bipolar transistor comprising the steps of: forming a collector region; forming a base-link diffusion source layer over a first portion of said collector region; depositing a first layer of polysilicon over said collector region and said base-link diffusion source layer; etching said first layer of polysilicon to form a base electrode overlying at least one end of said base-link diffusion source layer, wherein said base-link diffusion source layer acts as an etchstop; removing said base-link diffusion source layer except for said at least one end portion to expose a second portion of said collector region, said second portion within said first portion; diffusing an extrinsic base region from said base electrode and a base link-up region from said at least one end portion of said base link layer; and implanting an intrinsic base region into said second portion of said collector region.
Claim 11
Independent Claim
149 words
A method for forming a double polysilicon bipolar transistor comprising the steps of: forming a collector region; forming a base-link diffusion source layer over a first portion of said collector region; depositing a first layer of polysilicon over said collector region and said base-link diffusion source layer; etching said first layer of polysilicon to form a base electrode overlying at least one end of said base-link diffusion source layer, wherein said base-link diffusion source layer acts as an etchstop; removing said base-link diffusion source layer except for said at least one end portion to expose a second portion of said collector region, said second portion within said first portion; diffusing an extrinsic base region from said base electrode and a base link-up region from said at least one end portion of said base link layer; and implanting an intrinsic base region into said second portion of said collector region.
Claim 12
Dependent Claim
41 words
The method of claim 9, further comprising the steps of: forming a base-emitter spacer adjacent said base electrode; forming an emitter electrode over said intrinsic base region and said base-emitter spacer; and forming an emitter region within said intrinsic base region.
Claim 13
Dependent Claim
15 words
The method of claim 9, wherein said base-link diffusion source layer comprises a silicate glass.
Claim 14
Dependent Claim
14 words
The method of claim 9, wherein said base-link diffusion source layer comprises borosilicate glass.
Claim 15
Dependent Claim
15 words
The method of claim 9, wherein said base-link diffusion source layer comprises a phosphosilicate glass.
Claim 16
Dependent Claim
13 words
The method of claim 9, wherein said base-link diffusion source layer comprises silicon-germanium.
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) | 2000-03-31 | 2000-09-30 | 2001-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-31 | 2004-09-30 | 2005-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-31 | 2008-09-30 | 2009-04-01 | $7700.00 | Window Closed / Lapsed |