US5374846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bipolar transistor with a particular base and collector regions
Assignee: NEC Electronics Corp
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Filing: 1993-08-18
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Granted: 1994-12-20
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Expires: 2013-08-18
Abstract
Abstract A silicon film 9 and an N + -type impurity region 9a are provided between a base region 11 and an epitaxial growth layer 3. A silicon oxide film 12 is provided on the inner sidewalls of an opening 16, and an N-type polycrystalline silicon film 13 and an emitter region 15 are provided in the region surrounded by the silicon oxide film 12. The silicon film 9 is formed by means of a molecular beam epitaxy and the N-type impurity region 9a is formed prior to the formation of the base region 11 by means of ion implantation that uses a silicon oxide film 7 as the mask. As a result, it is possible to suppress the reduction in the cut-off frequency, and reduce the capacity between the base and the collector, so that a high speed operation of the bipolar transistor becomes possible.
Inventors
- 👤 Hisashi Takemura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:20
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/051; H10D10/054; H10D10/40; H10D10/441; H10D62/00; H10D62/10; H10D62/13; H10D62/137; H10D62/138
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
194 words
A semiconductor device comprising a collector region, a first insulating film covering said collector region, a first hole provided in said first insulating film to expose a part of said collector region, a semiconductor layer formed on said part of said collector region and defined by said first hole, a base region formed on said semiconductor layer and defined by said first hole, an emitter region selectively formed in said base region, said semiconductor layer having a first portion and a second portion surrounding said first portion, said first portion facing said emitter region and having a conductivity type equal to said collector region and an impurity concentration which is higher than an impurity concentration of said second portion, said first portion being in direct contact with said base region to form a PN junction between said first portion and said base region, a polysilicon conductive layer formed on said first insulating film and having a portion projecting from an edge of said first hole over said base region, and a conductive layer formed between said portion of said polysilicon layer and a part of said base region to form a conductive path therebetween.
Claim 2
Dependent Claim
194 words
A semiconductor device comprising a collector region, a first insulating film covering said collector region, a first hole provided in said first insulating film to expose a part of said collector region, a semiconductor layer formed on said part of said collector region and defined by said first hole, a base region formed on said semiconductor layer and defined by said first hole, an emitter region selectively formed in said base region, said semiconductor layer having a first portion and a second portion surrounding said first portion, said first portion facing said emitter region and having a conductivity type equal to said collector region and an impurity concentration which is higher than an impurity concentration of said second portion, said first portion being in direct contact with said base region to form a PN junction between said first portion and said base region, a polysilicon conductive layer formed on said first insulating film and having a portion projecting from an edge of said first hole over said base region, and a conductive layer formed between said portion of said polysilicon layer and a part of said base region to form a conductive path therebetween.
Claim 3
Dependent Claim
56 words
The device as claimed in claim 1, further comprising a second insulating film covering said polysilicon layer and said conductive layer, a second hole formed in said second insulating film to expose a part of said emitter region, and an emitter electrode formed in contact with said part of said emitter region through said second hole.
Claim 4
Dependent Claim
16 words
The device as claimed in claim 2, wherein said conductive layer comprises a polycrystalline semiconductor film.
Claim 5
Dependent Claim
44 words
The device as claimed in claim 2, wherein said conductive layer comprises a polycrystalline semiconductor film formed in contact with said polysilicon layer and a monocrystalline semiconductor film formed between said polycrystalline semiconductor layer and said part of said base region in contact therewith.
Claim 6
Dependent Claim
86 words
The device as claimed in claim 2, wherein said collector region includes a first layer having said portion exposed by said first hole and a second layer having an impurity concentration higher than an impurity concentration of said first layer, said first layer further having an active portion formed between said first portion of said semiconductor layer and said second layer in contact therewith, said active portion having an impurity concentration which is higher than the impurity concentration of a remaining portion of said first layer.
Claim 7
Dependent Claim
274 words
A semiconductor device comprising a collector region having a first layer and a second layer formed on said first layer and having an impurity concentration which is lower than the impurity concentration of said first layer, a first insulating film formed on said first layer of said collector region, a first hole selectively formed in said first insulating film to expose a part of said second layer, a semiconductor layer formed on said part of said second layer and defined by said first hole, a base region formed on said semiconductor layer and defined by said first hole, an emitter region selectively formed in said base region, said semiconductor layer having a first portion and a second portion surrounding said first portion, said first portion facing said emitter region and having a conductivity type equal to said collector region and an impurity concentration which is higher than the impurity concentration of said second portion, said first portion being in direct contact with said base region to form a PN junction between said first portion and said base region, said second layer having an active portion having an impurity concentration which is higher than the impurity concentration of a remaining portion of said second layer and being formed between said first portion of said semiconductor layer and said first layer of said collector region in contact therewith, a polysilicon layer formed on said first insulating film and having a portion projecting from an edge of said first hole over said base region, and a polycrystalline semiconductor film formed between said portion of said polysilicon layer and a part of said base region in contact therewith.
Claim 8
Dependent Claim
274 words
A semiconductor device comprising a collector region having a first layer and a second layer formed on said first layer and having an impurity concentration which is lower than the impurity concentration of said first layer, a first insulating film formed on said first layer of said collector region, a first hole selectively formed in said first insulating film to expose a part of said second layer, a semiconductor layer formed on said part of said second layer and defined by said first hole, a base region formed on said semiconductor layer and defined by said first hole, an emitter region selectively formed in said base region, said semiconductor layer having a first portion and a second portion surrounding said first portion, said first portion facing said emitter region and having a conductivity type equal to said collector region and an impurity concentration which is higher than the impurity concentration of said second portion, said first portion being in direct contact with said base region to form a PN junction between said first portion and said base region, said second layer having an active portion having an impurity concentration which is higher than the impurity concentration of a remaining portion of said second layer and being formed between said first portion of said semiconductor layer and said first layer of said collector region in contact therewith, a polysilicon layer formed on said first insulating film and having a portion projecting from an edge of said first hole over said base region, and a polycrystalline semiconductor film formed between said portion of said polysilicon layer and a part of said base region in contact therewith.
Claim 9
Dependent Claim
57 words
The device as claimed in claim 6, further comprising a second insulating film cover said polysilicon layer and said polycrystalline semiconductor film, a second hole formed in said second insulating film to expose a part of said emitter region, and an emitter electrode formed in contact with said part of said emitter region through said second hole.
Claim 10
Dependent Claim
36 words
The device as claimed in claim 7, wherein said emitter electrode comprises a polycrystalline silicon layer formed in contact with said part of said emitter region and a metal layer formed on said polycrystalline silicon layer.
Claim 11
Dependent Claim
212 words
A semiconductor device comprising a collector region, a first insulating film covering said collector region, a first hole provided in said first insulating film to expose a part of said collector region, a semiconductor layer formed on said part of said collector region and defined by said first hole, a base region formed on said semiconductor layer and defined by said first hole, an emitter region selectively formed in said base region, said semiconductor layer having a first portion and a second portion surrounding said first portion, said first portion facing said emitter region and having a conductivity type equal to a conductivity type of said collector region and an impurity concentration which is higher than an impurity concentration of said second portion, a polysilicon conductive layer formed on said first insulating film and having a portion projecting from an edge of said first hole and over said base region, and a conductive layer formed between said portion of said polysilicon layer and a part of said base region to form a conductive path therebetween, said base region having a first bottom portion located under said emitter region and a second bottom portion located under said conductive layer and said first and second bottom portions being uniform in depth with each other.
Claim 12
Dependent Claim
212 words
A semiconductor device comprising a collector region, a first insulating film covering said collector region, a first hole provided in said first insulating film to expose a part of said collector region, a semiconductor layer formed on said part of said collector region and defined by said first hole, a base region formed on said semiconductor layer and defined by said first hole, an emitter region selectively formed in said base region, said semiconductor layer having a first portion and a second portion surrounding said first portion, said first portion facing said emitter region and having a conductivity type equal to a conductivity type of said collector region and an impurity concentration which is higher than an impurity concentration of said second portion, a polysilicon conductive layer formed on said first insulating film and having a portion projecting from an edge of said first hole and over said base region, and a conductive layer formed between said portion of said polysilicon layer and a part of said base region to form a conductive path therebetween, said base region having a first bottom portion located under said emitter region and a second bottom portion located under said conductive layer and said first and second bottom portions being uniform in depth with each other.
Claim 13
Dependent Claim
36 words
The device as claimed in claim 9, wherein said first portion of said semiconductor layer is in direct contact with said base region to form a PN junction between said first portion and said base region.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-12-19 | 1998-06-20 | 1998-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-19 | 2002-06-20 | 2002-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-19 | 2006-06-20 | 2006-12-20 | $7700.00 | Window Closed / Lapsed |