US4500903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor GTO switching device with radially elongated cathode emitter regions of increasing length
Assignee: Hitachi Ltd
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Filing: 1982-06-03
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Granted: 1985-02-19
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Expires: 2002-06-03
Abstract
Abstract A gate turn-off thyristor in which a cathode-emitter layer is divided into a plurality of strip-like regions which are radially arrayed on a major surface of a semiconductor substrate in a coaxial multi-ring pattern including a plurality of coaxially arrayed rings. The cathode-emitter strips belonging to a given one of the rings have some radial length. The cathode-emitter strips belonging to the inner ring of a coaxial multi-ring pattern have a smaller radial length than that of the cathode-emitter strips constituting the outer ring. A cathode electrode is contacted to the cathode-emitter strip in low resistance ohmic contact. A gate electrode is ohmic contacted with a low resistance to a cathode-base layer located adjacent to the cathode-emitter strip so as to enclose it. An anode electrode is ohmic contacted with a low resistance to the anode-emitter layer. With the structure of GTO, turn-off operation of unit GTO's each including a cathode-emitter strip is equalized.
Inventors
- 👤 Tsutomu Yatsuo
- 👤 Takahiro Nagano
- 👤 Saburo Oikawa
- 👤 Akira Horie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:37
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/141; H10D62/148; H10D18/00; H10D18/60
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
170 words
A semiconductor switching device comprising: (a) a semiconductor substrate including a cathode-emitter layer, a cathode-base layer, an anode-base layer and an anode-emitter layer, said layers having conductivity types differing alternately from one another between the adjacent layers; (b) said cathode-emitter layer being divided into a plurality of strip-like cathode-emitter regions which are arrayed on a major surface of said semiconductor substrate in a coaxial multi-ring pattern, each cathode-emitter region being elongated along the radial direction of the ring; (c) the strip-like cathode-emitter regions which constitute an inner ring in said coaxial multi-ring pattern having a length in said radial direction shorter than the length in the radial direction of strip-like cathode-emitter regions constituting an outer ring in said multi-ring pattern; (d) cathode electrodes contacted to said strip-like cathode emitter regions in low resistance contact; (e) gate electrodes disposed so as to enclose said strip-like cathode-emitter regions and contacted to said cathode-emitter regions in low resistance contact; and (f) an anode electrode contacted to said anode-emitter layer in low resistance contact.
Claim 2
Dependent Claim
170 words
A semiconductor switching device comprising: (a) a semiconductor substrate including a cathode-emitter layer, a cathode-base layer, an anode-base layer and an anode-emitter layer, said layers having conductivity types differing alternately from one another between the adjacent layers; (b) said cathode-emitter layer being divided into a plurality of strip-like cathode-emitter regions which are arrayed on a major surface of said semiconductor substrate in a coaxial multi-ring pattern, each cathode-emitter region being elongated along the radial direction of the ring; (c) the strip-like cathode-emitter regions which constitute an inner ring in said coaxial multi-ring pattern having a length in said radial direction shorter than the length in the radial direction of strip-like cathode-emitter regions constituting an outer ring in said multi-ring pattern; (d) cathode electrodes contacted to said strip-like cathode emitter regions in low resistance contact; (e) gate electrodes disposed so as to enclose said strip-like cathode-emitter regions and contacted to said cathode-emitter regions in low resistance contact; and (f) an anode electrode contacted to said anode-emitter layer in low resistance contact.
Claim 3
Dependent Claim
51 words
A semiconductor switching device according to claim 1, wherein a ratio of the radial length of the strip-like cathode-emitter regions constituting a given one of the rings of said coaxial multi-ring pattern to the radius of said given ring is substantially invariable among the rings included in said coaxial multi-ring pattern.
Claim 4
Dependent Claim
26 words
A semiconductor switching device according to claim 1, wherein distance between two adjacent strip-like cathode-emitter regions is of an invariable value throughout all of said rings.
Claim 5
Dependent Claim
39 words
A semiconductor switching device according to claim 1, wherein said anode-emitter layer is present at least at locations immediately below said strip-like cathode-emitter regions as viewed in the direction in which said cathode-emitter regions is projected toward the anode.
Claim 6
Dependent Claim
28 words
A semiconductor switching device according to claim 1, wherein a gate electrode to be supplied with a gate signal is positioned at the center of said semiconductor substrate.
Claim 7
Dependent Claim
37 words
A semiconductor switching device according to claim 1, wherein a gate electrode to be supplied with a gate signal is located at an intermediate portion between the rings of said cathode-emitter regions of said coaxial multi-ring pattern.
Claim 8
Dependent Claim
91 words
In a semiconductor thyristor device of pnpn type formed in a semiconductor substrate and including a multiplicity of elongated n type cathode-emitter regions disposed in a multi-ring configuration, each ring being constituted by a plurality of cathode-emitter regions, each cathode emitter region being oriented to be elongated along the radial direction of the ring with respect to a center of said ring configuration, a cathode-emitter structure comprising: said cathode-emitter regions having respective radial lengths which monotonically increase with the distance of the cathode-emitter region from the center of said multi-ring configuration.
Claim 9
Dependent Claim
91 words
In a semiconductor thyristor device of pnpn type formed in a semiconductor substrate and including a multiplicity of elongated n type cathode-emitter regions disposed in a multi-ring configuration, each ring being constituted by a plurality of cathode-emitter regions, each cathode emitter region being oriented to be elongated along the radial direction of the ring with respect to a center of said ring configuration, a cathode-emitter structure comprising: said cathode-emitter regions having respective radial lengths which monotonically increase with the distance of the cathode-emitter region from the center of said multi-ring configuration.
Claim 10
Dependent Claim
48 words
A cathode-emitter structure according to claim 7, wherein said cathode-emitter regions are so disposed that each pair of adjacent cathode-emitter regions are distanced from one another by substantially constant distances at an inner end, at a mid position and at an outer end regardless of the ring position.
Claim 11
Dependent Claim
151 words
A semiconductor switching device according to claim 1, wherein said multi-ring pattern comprises at least three coaxial rings R 1 , R 2 and R 3 , arranged with the ring R 1 being closest to the center of said coaxial rings, the ring R 3 being farthest from said center and said ring R 2 being between said rings R 1 and R 3 , and further wherein the respective radial lengths of said strip-like cathode-emitter regions in a direction elongated along the radial direction of the ring are set according to the relation: lR.sub.1 <lR.sub.2 <lR.sub.3 where lR 1 is the radial length of the strip-like cathode-emitter regions of the ring R 1 , lR 2 is the radial length of the strip-like cathode-emitter regions of the ring R 2 ; and lR 3 is the radial length of the strip-like cathode-emitter regions of the ring R 3 .
Claim 12
Dependent Claim
58 words
A semiconductor switching device according to claim 1, wherein the respective lengths of the strip-like cathode emitter regions in said inner and outer rings are set to provide a substantially uniform turn-off time and on-state voltage for unit GTO's formed by each of said strip-like cathode-emitter regions with said cathode-base layer, said anode-base layer and said anode-emitter layer.
Claim 13
Dependent Claim
58 words
A semiconductor switching device according to claim 9, wherein the respective lengths of the strip-like cathode emitter regions in said at least three rings are set to provide a substantially uniform turn-off time and on-state voltage for unit GTO's formed by each of said strip-like cathode-emitter regions with said cathode-base layer, said anode-base layer and said anode-emitter layer.
References Cited (Backward Citations)
JPS507427A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-19 | 1988-08-20 | 1989-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-19 | 1992-08-20 | 1993-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-19 | 1996-08-20 | 1997-02-19 | $7700.00 | Window Closed / Lapsed |