EP0525762A2
Expired / Lapsed
EP
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Microwave heterojunction bipolar transistors suitable for low-power, low-noise and high-power applications and method for fabricating same
Assignee: Texas Instruments Inc
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Filing: 1992-07-30
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Granted: —
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Expires: 2012-07-30
Abstract
Abstract Generally, and in one form of the invention, a microwave heterojunction bipolar transistor suitable for low-power, low-noise and high-power applications having an emitter 108, a base 126 and a collector 24 is disclosed, wherein the base 126 is composed of one or more islands 126 of semiconductor material. The one or more islands 126 are formed so that they do not cross any boundaries of the active area 60 of the transistor. Other devices, systems and methods are also disclosed.
Inventors
- 👤 Burhan Bayraktaroglu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 14:06
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/17; H10D62/177; H10D10/00; H10D10/01; H10D10/021; H10D10/80; H10D10/821; H10D62/80; H10D62/85
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
44 words
A microwave heterojunction bipolar transistor suitable for low-power, low-noise and high-power applications having an emitter, a base and a collector, wherein said base is at least one island of semiconductor material, said island not crossing any boundaries of an active area of said transistor.
Claim 2
Dependent Claim
44 words
A microwave heterojunction bipolar transistor suitable for low-power, low-noise and high-power applications having an emitter, a base and a collector, wherein said base is at least one island of semiconductor material, said island not crossing any boundaries of an active area of said transistor.
Claim 3
Dependent Claim
21 words
The microwave heterojunction bipolar transistor of Claim 1 wherein said at least one base island is contacted by an air bridge.
Claim 4
Dependent Claim
35 words
The microwave heterojunction bipolar transistor of Claim 1 wherein said emitter is at least one island of semiconductor material, said at least one island not crossing any boundaries of said active area of said transistor.
Claim 5
Dependent Claim
129 words
A microwave heterojunction bipolar transistor suitable for low-power, low-noise and high-power applications, comprising: a semi-insulating semiconductor substrate; a collector layer of a first conductivity type disposed on said substrate; at least one base island of a second conductivity type disposed on said collector layer; an active area defined in said substrate, said collector layer and completely encompassing said at least one base island; an emitter of said first conductivity type disposed on said at least one base island and having a wider energy bandgap than said at least one base island; and conductive contacts disposed on said collector layer, said at least one base island and said emitter, wherein said at least one base island is disposed on said collector layer without crossing any boundaries of said active area.
Claim 6
Dependent Claim
129 words
A microwave heterojunction bipolar transistor suitable for low-power, low-noise and high-power applications, comprising: a semi-insulating semiconductor substrate; a collector layer of a first conductivity type disposed on said substrate; at least one base island of a second conductivity type disposed on said collector layer; an active area defined in said substrate, said collector layer and completely encompassing said at least one base island; an emitter of said first conductivity type disposed on said at least one base island and having a wider energy bandgap than said at least one base island; and conductive contacts disposed on said collector layer, said at least one base island and said emitter, wherein said at least one base island is disposed on said collector layer without crossing any boundaries of said active area.
Claim 7
Dependent Claim
35 words
The microwave heterojunction bipolar transistor of Claim 4 wherein said emitter is at least one island of semiconductor material, said at least one island not crossing any boundaries of said active area of said transistor.
Claim 8
Dependent Claim
148 words
A monolithic microwave integrated circuit (MMIC) including a plurality of electrically interconnected microwave heterojunction bipolar transistors suitable for low-power, low-noise and high-power applications disposed on a semi-insulating semiconductor substrate wherein each of said transistors comprises: a collector layer of a first conductivity type disposed on said substrate; at least one base island of a second conductivity type disposed on said collector layer; an active area defined in said substrate, said collector layer and completely encompassing said at least one base island; an emitter island of said first conductivity type disposed on said at least one base island and having a wider energy bandgap than said at least one base island; and conductive contacts disposed on said collector layer, said at least one base island and said emitter, wherein said at least one base island is disposed on said collector layer without crossing any boundaries of said active area.
Claim 9
Dependent Claim
148 words
A monolithic microwave integrated circuit (MMIC) including a plurality of electrically interconnected microwave heterojunction bipolar transistors suitable for low-power, low-noise and high-power applications disposed on a semi-insulating semiconductor substrate wherein each of said transistors comprises: a collector layer of a first conductivity type disposed on said substrate; at least one base island of a second conductivity type disposed on said collector layer; an active area defined in said substrate, said collector layer and completely encompassing said at least one base island; an emitter island of said first conductivity type disposed on said at least one base island and having a wider energy bandgap than said at least one base island; and conductive contacts disposed on said collector layer, said at least one base island and said emitter, wherein said at least one base island is disposed on said collector layer without crossing any boundaries of said active area.
Claim 10
Dependent Claim
21 words
The monolithic microwave integrated circuit in either of Claims 4 or 6 wherein said active area is defined by ion implantation.
Claim 11
Dependent Claim
26 words
The monolithic microwave integrated circuit in any of Claims 1, 4 or 6 wherein said at least one base island is surrounded by a non-conductive area.
Claim 12
Dependent Claim
28 words
The monolithic microwave integrated circuit of Claim 8 wherein said at least one base island is contacted by a conductive layer at least partially overlying said non-conductive area.
Claim 13
Dependent Claim
28 words
The monolithic microwave integrated circuit in either of Claims 4 or 6 wherein said conductive contact disposed on said at least one base island is an air bridge.
Claim 14
Dependent Claim
32 words
The monolithic microwave integrated circuit of Claim 6 wherein said emitter is at least one island of semiconductor material, said at least one island not crossing any boundaries of said active area.
Claim 15
Independent Claim
145 words
A method of making a microwave heterojunction bipolar transistor suitable for low-power, low-noise and high-power applications, comprising the steps of: providing a semi-insulating semiconductor substrate; depositing a collector layer of a first conductivity type on said substrate; depositing a base layer of a second conductivity type on said collector layer; depositing an emitter layer of said first conductivity type on said base layer, said emitter layer having a wider energy bandgap than said base layer; defining an active area in said substrate, said collector layer, said base layer and said emitter layer; defining an emitter region in said emitter layer; defining at least one base island in said base layer such that boundaries of said at least one base island do not cross boundaries of said active area; and forming conductive contacts on said collector layer, said at least one base island and said emitter.
Claim 16
Independent Claim
145 words
A method of making a microwave heterojunction bipolar transistor suitable for low-power, low-noise and high-power applications, comprising the steps of: providing a semi-insulating semiconductor substrate; depositing a collector layer of a first conductivity type on said substrate; depositing a base layer of a second conductivity type on said collector layer; depositing an emitter layer of said first conductivity type on said base layer, said emitter layer having a wider energy bandgap than said base layer; defining an active area in said substrate, said collector layer, said base layer and said emitter layer; defining an emitter region in said emitter layer; defining at least one base island in said base layer such that boundaries of said at least one base island do not cross boundaries of said active area; and forming conductive contacts on said collector layer, said at least one base island and said emitter.
Claim 17
Dependent Claim
21 words
The method of making a microwave heterojunction bipolar transistor of Claim 12 further including defining said active area by ion implantation.
Claim 18
Independent Claim
181 words
A method of making a monolithic microwave integrated circuit (MMIC) including a plurality of microwave heterojunction bipolar transistor suitable for low-power, low-noise and high-power applications, comprising the steps of: providing a semi-insulating semiconductor substrate; depositing a collector layer of a first conductivity type on said substrate; depositing a base layer of a second conductivity type on said collector layer; depositing an emitter layer of said first conductivity type on said base layer, said emitter layer having a wider energy bandgap than said base layer; defining a plurality of active areas corresponding to the locations of said transistors in said substrate, said collector layer, said base layer and said emitter layer; defining an emitter region in said emitter layer in each of said active areas; defining at least one base island in said base layer in each of said active areas such that boundaries of said at least one base island do not cross boundaries of said active areas; forming conductive contacts on said collector layer, said at least one base island and said emitter; and forming electrical interconnections between said transistors.
Claim 19
Independent Claim
181 words
A method of making a monolithic microwave integrated circuit (MMIC) including a plurality of microwave heterojunction bipolar transistor suitable for low-power, low-noise and high-power applications, comprising the steps of: providing a semi-insulating semiconductor substrate; depositing a collector layer of a first conductivity type on said substrate; depositing a base layer of a second conductivity type on said collector layer; depositing an emitter layer of said first conductivity type on said base layer, said emitter layer having a wider energy bandgap than said base layer; defining a plurality of active areas corresponding to the locations of said transistors in said substrate, said collector layer, said base layer and said emitter layer; defining an emitter region in said emitter layer in each of said active areas; defining at least one base island in said base layer in each of said active areas such that boundaries of said at least one base island do not cross boundaries of said active areas; forming conductive contacts on said collector layer, said at least one base island and said emitter; and forming electrical interconnections between said transistors.
Claim 20
Dependent Claim
23 words
The method of making a monolithic microwave integrated circuit of Claim 14 further including defining said plurality of active areas by ion implantation.
Claim 21
Independent Claim
29 words
The method of making a monolithic microwave integrated circuit in either of Claims 12 or 14 further including forming a non-conductive region surrounding said at least one base island.
Claim 22
Independent Claim
38 words
The method of making a monolithic microwave integrated circuit in either of Claims 12 or 14 further including forming said conductive contacts disposed on said at least one base island to at least partially overlay said non-conductive region.
Claim 23
Independent Claim
35 words
The method of making a monolithic microwave integrated circuit in either of Claims 12 or 14 further including forming said conductive contacts disposed on said at least one base island to be an air bridge.
Claim 24
Independent Claim
51 words
The method of making a monolithic microwave integrated circuit in either of Claims 12 or 14 wherein said defining an emitter step includes defining at least one emitter island in said emitter layer such that boundaries of said at least one emitter island do not cross boundaries of said active area.
References Cited (Backward Citations)
No citation records indexed.
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