Patent EP0240307A2 successfully refreshed from Google Patents.
EP0240307A2
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EP
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Bipolar transistor and method of producing the same
Assignee: Panasonic Holdings Corp
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Filing: 1987-03-31
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Granted: —
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Expires: 2007-03-31
Abstract
Abstract A dummy emitter (a dummy collector, in inverted type) is formed in the portion corresponding to an emitter (a collector, in inverted type) region, on a multiplayer structural material comprising layers for forming emitter, base and collector, and using it as mask, an external base region is exposed by etching, and a projection of emitter (collector, in inverted type) region is formed, while the dummy emitter (the dummy collector, in inverted type) is inverted into an emitter (a collector, in inverted type) electrode, thereby forming an emitter (a collector, in inverted type) electrode metal layer to cover the whole upper surface of the emitter (the collector, in inverted type). Using thus formed emitter (collector, in inverted type) electrode metal layer, a base electrode metal layer is formed, by self-alignment, adjacently to the emitter (the collector, in inverted type). In other method, on a multilayer structural material, impurities are introduced outside the portion corresponding to the base region of a bipolar transistor in order to insulate, at least, the layer to form the emitter, the layer to form the base, or at most, these layers and the layer to form the collector, and an extension type dummy emitter (dummy collector, in inverted type) extending from the emitter (collector, in inverted type) portion to the insulating region formed by transforming from the semiconductor material to form the emitter (the collector, in inverted type), and using it as mask, the external base region is exposed to form a projection coupling the emitter region and insulating region, and the dummy emitter (the dummy collector, in inverted type) is inverted to transform into an emitter (a collector, in inverted type) electrode metal layer to cover the whole upper surface of the projection.
Inventors
- 👤 Masanori Inada
- 👤 Kazuo Eda
- 👤 Yorito Ota
- 👤 Atsushi Nakagawa
- 👤 Manabu Yanagihara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 16:52
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/021; H10D10/80; H10D10/821; H10D62/00; H10D62/10; H10D62/13; H10D62/133; H10D64/00; H10D64/20; H10D64/23; H10D64/231; H10D62/80; H10D62/85; Y; Y10; Y10S; Y10S148/00; Y10S148/01; Y10S148/072
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
134 words
A bipolar transistor composed of a multilayer structural material having at least a second layer of semiconductor material for forming a base and a first layer and a third layer of semiconductor material having majority carriers different from the type of majority carriers of base region of the second layer formed in a sequence of the first layer, second layer and third layer on a substrate, comprising at least an insulation region made of the material of the second layer in the peripheral part of base region of the second layer, a projection made of the material of the third layer existing in conjunction with the portion of said base region and said insulating region, and electrode metal layer for the third layer of covering at least the entire upper surface of said projection.
Claim 2
Dependent Claim
134 words
A bipolar transistor composed of a multilayer structural material having at least a second layer of semiconductor material for forming a base and a first layer and a third layer of semiconductor material having majority carriers different from the type of majority carriers of base region of the second layer formed in a sequence of the first layer, second layer and third layer on a substrate, comprising at least an insulation region made of the material of the second layer in the peripheral part of base region of the second layer, a projection made of the material of the third layer existing in conjunction with the portion of said base region and said insulating region, and electrode metal layer for the third layer of covering at least the entire upper surface of said projection.
Claim 3
Dependent Claim
25 words
A bipolar transistor as set forth in claim 1, wherein the emitter is made of a semiconductor material greater in band gap than the base.
Claim 4
Dependent Claim
36 words
A bipolar transistor as set forth in claim 1, wherein a semiconductor material layer of fourth layer is possessed between the projection of third layer and electrode metal layer in order to form an ohmic contact.
Claim 5
Dependent Claim
31 words
A bipolar transistor as set forth in claim 1, wherein an insulating region made of material of third layer coupled with second layer is possessed between second layer and fourth layer.
Claim 6
Dependent Claim
35 words
A bipolar transistor as set forth in claim 3, wherein there is an insulating region made of material of third layer and fourth layer, being coupled with the second layer and electrode metal material layer.
Claim 7
Dependent Claim
65 words
A bipolar transistor as set forth in claim 1, wherein a base electrode metal layer existing being extended from the peripheral insulating region of base region substantially to the end of base region just beneath the electrode metal layer of projection made of material of third layer, and the projection made of material of third layer are present being isolated from said base electrode layer.
Claim 8
Dependent Claim
42 words
A bipolar transistor as set forth in claim 1, wherein there is a base electrode metal layer existing being extended until substantially contacting with the side wall made of insulating material provided around the projection made of the material of third layer.
Claim 9
Dependent Claim
45 words
A bipolar transistor as set forth in claim 1, wherein an external base region outside of the base region just beneath the electrode metal layer of the projection made of material of third layer possesses a smaller sheet resistance than said base region just beneath.
Claim 10
Dependent Claim
45 words
A bipolar transistor as set forth in claim 1, the external first layer outside of the first layer just beneath the electrode metal layer of the projection made of the material of third layer is the insulating region made of the material of first layer.
Claim 11
Independent Claim
163 words
A method of producing a bipolar transistor characterized at least by a step of forming a multilayer structural material by forming at least a second layer of semiconductor material for forming a base and a first layer and a third layer of semiconductor material possessing majority carriers different in type from majority carriers of base region of second layer in a sequence of the first layer, second layer and third layer on a substrate, a step of forming a dummy layer on the third layer, a step of forming a projection made of the material of the third layer by etching using said dummy layer as mask, and a step of forming an electrode metal layer for the third layer in an opening by forming an opening possessing the third layer exposed by covering the surface of the material having the dummy layer with a photosensitive resin exposing the upper part of the dummy layer by etching, and by removing said dummy layer.
Claim 12
Independent Claim
163 words
A method of producing a bipolar transistor characterized at least by a step of forming a multilayer structural material by forming at least a second layer of semiconductor material for forming a base and a first layer and a third layer of semiconductor material possessing majority carriers different in type from majority carriers of base region of second layer in a sequence of the first layer, second layer and third layer on a substrate, a step of forming a dummy layer on the third layer, a step of forming a projection made of the material of the third layer by etching using said dummy layer as mask, and a step of forming an electrode metal layer for the third layer in an opening by forming an opening possessing the third layer exposed by covering the surface of the material having the dummy layer with a photosensitive resin exposing the upper part of the dummy layer by etching, and by removing said dummy layer.
Claim 13
Dependent Claim
93 words
A method as set forth in claim 10, wherein a projection made of the material of the third layer and an external base region are formed by etching, using the dummy layer as mask, before forming the electrode metal layer for the third layer, and, after forming the electrode metal layer for the third layer, the base electrode metal is evaporated by using said electrode metal layer as mask, and the base electrode metal layer is formed substantially up to the end portion just beneath the electrode metal layer for the third layer.
Claim 14
Dependent Claim
81 words
A method as set forth in claim 11, wherein a side wall made of an insulating material is formed on the side of the electrode metal layer for the third layer and projection made of the material of the third layer, and a base electrode metal is evaporated using said electrode metal layer and side wall of said electrode metal layer as mask, thereby forming the base electrode metal layer substantially up to the end portion just beneath said side wall.
Claim 15
Dependent Claim
125 words
A method as set forth in claim 10, wherein a projection made of the material of the third layer and an external base region are formed by etching, using the dummy layer as mask, before forming the electrode metal layer for the third layer, a side wall made of an insulating material is formed on the side of said electrode metal layer and said projection after forming the electrode metal layer for the third layer, and the base electrode is made by evaporating the base electrode metal on the whole surface, by covering the surface with photosensitive resin, by exposing the projection possessing the side wall made of said insulating material by etching, and then by removing the base electrode metal depositing on said projection.
Claim 16
Dependent Claim
112 words
A method as set forth in claim 10, wherein a projection made of the material of the third layer is formed by etching up to the vicinity of the external base region by using dummy layer as mask before forming the electrode metal layer for the third layer, the external base region is exposed by etching, using said electrode layer as mask, after forming the electrode metal layer for the third layer, and forming a base electrode metal layer substantially up to the end portion just beneath the electrode metal layer for the third layer by evaporating the base electrode metal using said electrode metal layer for the third layer as mask.
Claim 17
Dependent Claim
76 words
A method as set forth in claim 10, wherein a projection made of the material of the third layer and an external base region are formed by etching, using the dummy layer as mask, before forming the electrode metal layer for the third layer, and a base electrode metal layer is formed substantially up to the end portion just beneath said dummy layer by evaporating the base electrode metal by using said dummy layer as mask.
Claim 18
Dependent Claim
109 words
A method as set forth in claim 10, wherein a projection made of the material of the third layer and an external base region are formed by etching, using the dummy layer as mask, before forming the electrode metal layer for the third layer, a side wall is formed on the sides of said dummy layer and the projection made of the material of third layer, the base electrode metal depositing on said side wall is removed by etching, after evaporating the base electrode metal on the entire surface, covering the surface with a photosensitive resin, and then exposing said projection by etching, and said side wall is removed.
Claim 19
Dependent Claim
36 words
A method as set forth in claim 10, wherein a low resistance external base region is formed by introducing impurities, using the dummy layer as mask, before forming the electrode metal layer for the third layer.
Claim 20
Dependent Claim
55 words
A method as set forth in claim 10, wherein an operating portion of a bipolar transistor made of first layer substantially of same size as dummy layer is formed by insulating part of the first layer by introducing impurities, using the dummy layer as mask, before forming the electrode metal layer for the third layer.
Claim 21
Dependent Claim
60 words
A method as set forth in claim 10, wherein an operating portion of a bipolar transistor made of first layer substantially of same size as electrode metal layer for the third layer is formed by insulating part of the first layer by introducing impurities, using electrode metal layer as mask, after forming the electrode metal layer for the third layer.
Claim 22
Dependent Claim
81 words
A method as set forth in claim 10, wherein a step of insulating the peripheral part of base region of second layer by introducing impurities, and a step of forming a dummy layer extending from the part of said base region to the peripheral part of said base region on the material made of the third layer are placed between a step of forming a multilayer structural material and a step of forming an electrode metal layer for the third layer.
References Cited (Backward Citations)
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