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US4968635A
Expired / Lapsed
US
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Method of forming emitter of a bipolar transistor in monocrystallized film
Assignee: Toshiba Corp
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Filing: 1988-09-16
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Granted: 1990-11-06
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Expires: 2008-09-16
Abstract
Abstract An emitter of a bipolar transistor is formed by depositing a polycrystalline or amorphous film on a substrate and monocrystallizing the deposited film. Further, the base region of the bipolar transistor is formed by ion implantation through the emitter region.
Inventors
- 👤 Toshihiko Hamasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:27
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/60; H10D10/00; H10D10/40; H10D10/441
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
117 words
A method of forming an emitter of a bipolar transistor in a monocrystallized film, comprising the steps of: providing a semiconductor substrate being a collector region and having a first conductivity; forming an insulating film on said substrate; forming an opening portion in said insulating film; forming a polycrystalline or amorphous film being an emitter region and having a higher impurity concentration of a first conductivity than the impurity concentration of said substrate; monocrystallizing the polycrystalline or amorphous semiconductor film using heat treatment; forming a region being a base region and having a lower impurity concentration of a second conductivity than that of said monocrystallized semiconductor film using ion implantation through the emitter region in said opening.
Claim 2
Independent Claim
117 words
A method of forming an emitter of a bipolar transistor in a monocrystallized film, comprising the steps of: providing a semiconductor substrate being a collector region and having a first conductivity; forming an insulating film on said substrate; forming an opening portion in said insulating film; forming a polycrystalline or amorphous film being an emitter region and having a higher impurity concentration of a first conductivity than the impurity concentration of said substrate; monocrystallizing the polycrystalline or amorphous semiconductor film using heat treatment; forming a region being a base region and having a lower impurity concentration of a second conductivity than that of said monocrystallized semiconductor film using ion implantation through the emitter region in said opening.
Claim 3
Dependent Claim
29 words
The method according to claim 1, wherein said semiconductor substrate is a monocrystalline silicon substrate and said polycrystalline or amorphous semiconductor film is a polycrystalline or amorphous silicon film.
Claim 4
Dependent Claim
41 words
Method according to claim 2, wherein said polycrystalline or amorphous silicon film containing the first conductivity type impurity is formed by a chemical gasphase growth method using a gas mixture composed of the 1st conductivity type impurity gas and Si gas.
Claim 5
Dependent Claim
21 words
The method according to claim 1, wherein said heat treatment is preformed at a temperature of 650° C. to 710° C.
Claim 6
Dependent Claim
27 words
The method of claim 1, wherein said monocrystallizing step further comprises a step of implanting silicon ions into the polycrystalline or amorphous semiconductor film before heat treatment.
Claim 7
Independent Claim
113 words
A method of forming an emitter of a bipolar transistor in a monocrystallized film, comprising the steps of: providing a monocrystalline silicon substrate being a collector region and having a first conductivity; forming an insulating film on said substrate; forming an opening portion in the insulating film; forming a polycrystalline silicon film being an emitter region on the substrate; amorphizing the polycrystalline silicon film using ion implantation of said first conductivity type impurity; monocrystallizing the amorphorized polycrystalline silicon film using heat treatment; and forming a base region having a lower impurity concentration of a second conductivity than that of the monocrystallized emitter region using ion implantation through the emitter region in the opening.
Claim 8
Independent Claim
113 words
A method of forming an emitter of a bipolar transistor in a monocrystallized film, comprising the steps of: providing a monocrystalline silicon substrate being a collector region and having a first conductivity; forming an insulating film on said substrate; forming an opening portion in the insulating film; forming a polycrystalline silicon film being an emitter region on the substrate; amorphizing the polycrystalline silicon film using ion implantation of said first conductivity type impurity; monocrystallizing the amorphorized polycrystalline silicon film using heat treatment; and forming a base region having a lower impurity concentration of a second conductivity than that of the monocrystallized emitter region using ion implantation through the emitter region in the opening.
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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) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |