US4243999A
Expired / Lapsed
US
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Gate turn-off thyristor
Assignee: Toshiba Corp
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Filing: 1979-07-16
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Granted: 1981-01-06
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Expires: 1999-07-16
Abstract
Abstract A gate turn-off thyristor which comprises a semiconductor body having at least four contiguous layers, namely, a first layer of a first conductivity type, a second layer lying continguous to the first layer and having a second conductivity type, a third layer lying contiguous to the second layer and having said first conductivity type, and a fourth layer contiguous to the third layer and having said conductivity type; an anode electrode mounted on said first layer; a gate electrode formed on said third layer; and a cathode electrode deposited on said fourth layer, and in which the following two relations are satisfied: ρ·V.sub.j /ρ.sub.sb ≧ 10.5(v·cm) and ρ sb ≦ 35 (Ω/ ) where ρ sb = sheet resistance (Ω/ ) at the normal temperature of the third layer, V j = backward withstanding voltage (V) at a PN junction bertween the third and fourth layers, and ρ = specific resistance (Ω·cm) of the second layer.
Inventors
- 👤 Makoto Azuma
- 👤 Akio Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:55
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/60; H10D18/00; H10D18/241; H10D18/60; H10D18/80; H10D62/10; H10D62/17; H10D62/192; H10D62/206; H10D84/00; H10D84/101; H10D84/131; H10D84/135; H10D84/136
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
151 words
A gate turnoff thyristor which comprises a semiconductor body having at least four contiguous layers, namely, a first diffused layer of a first conductivity type, second layer lying contiguous to the first layer and having a second conductivity type, a third diffused layer lying contiguous to the second layer and having said first conductivity type, and a fourth diffused layer lying contiguous to the third layer and having said second conductivity type; an anode electrode mounted on said first layer; a gate electrode formed on said third layer; and a cathode electrode deposited on said fourth layer, and in which the following two equations are satisfied: ρ·V.sub.j /ρ.sub.sb ≧10.5(v·cm) and ρ.sub.sb ≦35(Ω/ ) where: ρ sb =sheet resistance (Ω/ ) at the normal temperature of the third layer V j =backward withstanding voltage (V) at a PN junction between the third and fourth layers ρ=specific resistance (Ω·cm) of the second layer.
Claim 2
Dependent Claim
151 words
A gate turnoff thyristor which comprises a semiconductor body having at least four contiguous layers, namely, a first diffused layer of a first conductivity type, second layer lying contiguous to the first layer and having a second conductivity type, a third diffused layer lying contiguous to the second layer and having said first conductivity type, and a fourth diffused layer lying contiguous to the third layer and having said second conductivity type; an anode electrode mounted on said first layer; a gate electrode formed on said third layer; and a cathode electrode deposited on said fourth layer, and in which the following two equations are satisfied: ρ·V.sub.j /ρ.sub.sb ≧10.5(v·cm) and ρ.sub.sb ≦35(Ω/ ) where: ρ sb =sheet resistance (Ω/ ) at the normal temperature of the third layer V j =backward withstanding voltage (V) at a PN junction between the third and fourth layers ρ=specific resistance (Ω·cm) of the second layer.
Claim 3
Dependent Claim
16 words
The GTO thyristor according to claim 1, wherein said fourth layer is of a mesa type.
Claim 4
Dependent Claim
16 words
The GTO thyristor according to claim 1, wherein said fourth layer is of a planar type.
Claim 5
Dependent Claim
16 words
The GTO thyristor according to claim 1, wherein said fourth layer is of a multi-emitter type.
Claim 6
Dependent Claim
47 words
The GTO thyristor according to claim 1, wherein said second layer comprises a first region lying contiguous to said first layer and having a high impurity concentration; and a second region lying contiguous to said third region and having a specific resistance ρ at the normal temperature.
Claim 7
Dependent Claim
63 words
The GTO thyristor according to claim 1, wherein said second layer comprises a first region of high impurity concentration lying contiguous to said first layer and including a surface contacting the anode electrode; a second region lying contiguous to said third regions and having a specific resistance ρ at the normal temperature; and said fourth layer has a surface contacting the cathode electrode.
Claim 8
Dependent Claim
49 words
The GTO thyristor according to claim 1, wherein said first layer is provided with a region of said second conductivity type whose surface contacts said anode electrode; and said third layer whose surface contacts said cathode electrode has a region of said second conductivity type contacting said gate electrode.
Claim 9
Dependent Claim
74 words
The GTO thyristor according to claim 1, wherein said first diffused layer is of a P conductivity type and acts as an anode layer, said second layer is of an N conductivity type and acts as a first base layer, said third diffused layer is of a P conductivity type and acts as a second base layer, and said fourth diffused layer is of an N conductivity type and acts as a cathode layer.
References Cited (Backward Citations)
US3609476A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |