US4563698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
SCR Having multiple gates and phosphorus gettering exteriorly of a ring gate
Assignee: Infineon Technologies Americas Corp
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Filing: 1982-08-12
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Granted: 1986-01-07
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Expires: 2002-08-12
Abstract
Abstract A controlled rectifier employing a ring gate and an auxiliary emitter is disclosed. Auxiliary gates of different sensitivity cooperate with the auxiliary emitter. The controlled rectifier has gallium-diffused junctions and a phosphorus-diffused emitter. Phosphorus gettering dots or rings are diffused into the gallium-diffused region at the upper surface of the device surrounding and beneath portions of the ring gate electrode. The ring gate electrode has a narrow finger which extends from its internal periphery and overlaps a narrow extension from the main central emitter in order to provide a non-injecting current path for the peripheral distributed capacitance current which flows during the application of forward voltage. The value of this current is proportional to the rate of application of voltage or dV/dt.
Inventors
- 👤 Anders Nilarp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:18
CPC Classifications
H; H10; H10D; H10D18/00; H10D18/221; H10D62/00; H10D62/10; H10D62/17; H10D62/192; H10D62/206
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
225 words
A controlled rectifier having a ring gate; said controlled rectifier comprising a wafer of monocrystalline semiconductor material having generally flat parallel first and second surfaces; said first surface containing a central emitter diffusion region having a generally flat cathode contact secured thereto; said emitter region being of one of the conductivity types; said emitter region being formed in and surrounded at said first surface by a second region which is of the other of the conductivity types; and a ring-shaped gate contact surrounding and radially spaced from the exterior of said central emitter diffusion region and from the exterior of said flat cathode contact; first and second auxiliary emitter regions of said one of said conductivity types formed in said first surface and circumferentially spaced from one another and at least partly underlying the outer periphery of said ring gate and in electrical contact with said ring gate and first and second auxiliary gate contacts connected to said first surface and on said second region; said first and second auxiliary gate contacts being disposed adjacent said first and second auxiliary regions respectively and having portions thereof spaced from said ring gate by different respective distances, whereby said first and second auxiliary gate contacts have different firing sensitivities only one of said first and second gate electrodes being selected for the operation of said controlled rectifier.
Claim 2
Dependent Claim
225 words
A controlled rectifier having a ring gate; said controlled rectifier comprising a wafer of monocrystalline semiconductor material having generally flat parallel first and second surfaces; said first surface containing a central emitter diffusion region having a generally flat cathode contact secured thereto; said emitter region being of one of the conductivity types; said emitter region being formed in and surrounded at said first surface by a second region which is of the other of the conductivity types; and a ring-shaped gate contact surrounding and radially spaced from the exterior of said central emitter diffusion region and from the exterior of said flat cathode contact; first and second auxiliary emitter regions of said one of said conductivity types formed in said first surface and circumferentially spaced from one another and at least partly underlying the outer periphery of said ring gate and in electrical contact with said ring gate and first and second auxiliary gate contacts connected to said first surface and on said second region; said first and second auxiliary gate contacts being disposed adjacent said first and second auxiliary regions respectively and having portions thereof spaced from said ring gate by different respective distances, whereby said first and second auxiliary gate contacts have different firing sensitivities only one of said first and second gate electrodes being selected for the operation of said controlled rectifier.
Claim 3
Dependent Claim
15 words
The device of claim 1, wherein said first and second auxiliary gates have different geometries.
Claim 4
Dependent Claim
38 words
The device of claim 1, wherein said ring gate has first and second circumferentially spaced cut-out regions extending into its outer periphery; said first and second auxiliary gates being nested into said first and second cut-out regions respectively.
Claim 5
Dependent Claim
38 words
The device of claim 2, wherein said ring gate has first and second circumferentially spaced cutout regions extending into its outer periphery; said first and second auxiliary gates being nested into said first and second cut-out regions respectively.
Claim 6
Dependent Claim
23 words
The controlled rectifier of claims 1, 2, 3 or 4, wherein said emitter region is circular and wherein said ring gate is circular.
Claim 7
Dependent Claim
20 words
The controlled rectifier of claims 1, 2, 3 or 4, which includes an anode contact connected to said second surface.
Claim 8
Dependent Claim
33 words
The device of claim 1, wherein said ring gate contact has a short peripheral portion thereof electrically connected to a short peripheral portion of the outer periphery of said central emitter diffusion region.
Claim 9
Dependent Claim
162 words
A controlled rectifier having a ring gate; said controlled rectifier comprising a wafer of monocrystalline semiconductor material having generally flat parallel first and second surfaces; said first surface containing a central emitter diffusion region having a generally flat cathode contact secured thereto; said emitter region being of one of the conductivity types; said emitter region being formed in and surrounded at said first surface by a second region which is of the other of the conductivity types; and a ring-shaped gate contact surrounding and radially spaced from the exterior of said central emitter diffusion region and from the exterior of said flat cathode contact; said second region being a gallium-diffused region; said emitter region being a phosphorus diffused region; and a plurality of spaced phosphorus diffused regions extending into said second region in areas external of the outer periphery of said ring gate which serve as gettering regions to increase minority carrier lifetime in said second region external of said ring gate.
Claim 10
Dependent Claim
162 words
A controlled rectifier having a ring gate; said controlled rectifier comprising a wafer of monocrystalline semiconductor material having generally flat parallel first and second surfaces; said first surface containing a central emitter diffusion region having a generally flat cathode contact secured thereto; said emitter region being of one of the conductivity types; said emitter region being formed in and surrounded at said first surface by a second region which is of the other of the conductivity types; and a ring-shaped gate contact surrounding and radially spaced from the exterior of said central emitter diffusion region and from the exterior of said flat cathode contact; said second region being a gallium-diffused region; said emitter region being a phosphorus diffused region; and a plurality of spaced phosphorus diffused regions extending into said second region in areas external of the outer periphery of said ring gate which serve as gettering regions to increase minority carrier lifetime in said second region external of said ring gate.
Claim 11
Dependent Claim
15 words
The device of claim 8 in which said spaced phosphorus diffused regions are concentric rings.
Claim 12
Dependent Claim
16 words
The device of claim 8 is in which said spaced phosphorus diffused regions are spaced dots.
Claim 13
Dependent Claim
128 words
The device of claim 8, 9 or 10 which further includes first and second auxiliary emitter regions of said one of said conductivity types formed in said first surface and circumferentially spaced from one another and at least partly underlying the outer periphery of said ring gate and in galvanic contact with said ring gate; and first and second auxiliary gate contacts connected to said first surface and on said second region; said first and second auxiliary gate contacts being adjacent said first and second auxiliary regions respectively and spaced from said ring gate by different respective distances, whereby said first and second auxiliary gate contacts have different firing sensitivities, only one of said first and second gate contacts being selected for the operation of said controlled rectifier.
Claim 14
Dependent Claim
32 words
The device of claim 11, wherein said ring gate has a short peripheral portion thereof electrically connected to a short peripheral portion of the outer periphery of said central emitter diffusion region.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-01-06 | 1989-07-08 | 1990-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-06 | 1993-07-08 | 1994-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-06 | 1997-07-08 | 1998-01-07 | $7700.00 | Window Closed / Lapsed |