US4288801A
Expired / Lapsed
US
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Monolithic HVMOSFET active switch array
Assignee: Xerox Corp
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Filing: 1979-05-30
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Granted: 1981-09-08
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Expires: 1999-05-30
Abstract
Abstract Integrated monolithic arrays of high voltage metal oxide semiconductor field effect transistors having closed geometry grounded peripheries for interdevice isolation are able to function as drivers that may be switched on and off. The HVMOSFET'S include DMOS-like structures with separate channel and drift regions, closed geometry configurations with center drains, and split oxide topography having relatively thick oxide under a field plate and over a drift region for surface depletion and high voltage field inversion preclusion respectfully. The infra described HVMOSFET includes an active load operatively connected in cascade and connecting to a device switch for forming an integrated HV Active Switch in a monolithic array.
Inventors
- 👤 Ram S. Ronen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:43
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/111; H10D64/115; H10D30/00; H10D30/60; H10D30/601; H10D30/603; H10D30/611; H10D62/00; H10D62/10; H10D62/124; H10D62/126; H10D62/13; H10D62/149; H10D62/151; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/514; H10D64/516; H10D64/517; H10D64/519; H10D64/60; H10D64/605
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
262 words
A HVMOSFET cascade switch structure having closed geometry in an integrated array on a monolithic substrate with relatively monotonicall decreasing voltage order from the center out, comprising: (a) first switch means having a first drain area formed in the substrate at its relative center with a relatively high voltage potential applied thereto, having a first source area formed in the substrate at its relative outer periphery at a predetermined distance and in concentric relation to the first drain, and having a first gate disposed at a predetermined distance and in concentric relation above a first channel formed in the substrate interposably at a predetermined distance and in concentric relation between the relative center and the outer periphery for connection to the first drain area for operation as an active MOS load of the structure relative to the substrate; and (b) second switch means having a second drain area formed in the substrate at its relative inner periphery that is operatively coincidently common with the first source area, having a fixed common ground voltage potential at a second source area formed in the substrate at the relative outer periphery at a predetermined distance and in concentric relation to the second drain, and having a second gate with a control input voltage potential applied thereto disposed at a predetermined distance and in concentric relation above a second channel formed in the substrate interposably at a predetermined distance and in concentric relation between the relative inner and outer peripheries for controlling the switching of an outputted relatively high voltage potential at the second drain area.
Claim 2
Dependent Claim
262 words
A HVMOSFET cascade switch structure having closed geometry in an integrated array on a monolithic substrate with relatively monotonicall decreasing voltage order from the center out, comprising: (a) first switch means having a first drain area formed in the substrate at its relative center with a relatively high voltage potential applied thereto, having a first source area formed in the substrate at its relative outer periphery at a predetermined distance and in concentric relation to the first drain, and having a first gate disposed at a predetermined distance and in concentric relation above a first channel formed in the substrate interposably at a predetermined distance and in concentric relation between the relative center and the outer periphery for connection to the first drain area for operation as an active MOS load of the structure relative to the substrate; and (b) second switch means having a second drain area formed in the substrate at its relative inner periphery that is operatively coincidently common with the first source area, having a fixed common ground voltage potential at a second source area formed in the substrate at the relative outer periphery at a predetermined distance and in concentric relation to the second drain, and having a second gate with a control input voltage potential applied thereto disposed at a predetermined distance and in concentric relation above a second channel formed in the substrate interposably at a predetermined distance and in concentric relation between the relative inner and outer peripheries for controlling the switching of an outputted relatively high voltage potential at the second drain area.
Claim 3
Dependent Claim
32 words
The HVMOSFET switch structure of claim 1 wherein the voltage potential decreases relatively monotonically from the relative center of said active load first switch means to said second drive switch means respectively.
Claim 4
Dependent Claim
19 words
The HVMOSFET switch structure of claim 1 further including oxide means relatively disposed over the structure for electrical isolation.
Claim 5
Dependent Claim
14 words
The HVMOSFET switch structure of claim 3 wherein said oxide means is relatively thick.
Claim 6
Dependent Claim
31 words
The HVMOSFET switch structure of claim 3 wherein said oxide means is relatively thick over said first switch active loads means and relatively split oxide over said second switch driver means.
Claim 7
Dependent Claim
71 words
The HVMOSFET switch structure of claim 5 wherein the relatively split oxide of said oxide means has a thin portion disposed over the channel area and under the second gate that is relatively adjacent to the source area at the relatively outer periphery and a thick portion disposed over the substrate between the channel area and the drain area at the relative inner periphery of said second switch driver switch means.
Claim 8
Dependent Claim
61 words
The HVMOSFET switch structure of claim 6 and 3 further including field plate means relatively disposed over the thick portion of the relatively split oxide of said oxide means and relatively interdisposed between the relative inner and outer periphery of said driver second switch means for directing field lines away from the relative inner periphery of said driver second switch means.
Claim 9
Dependent Claim
28 words
The HVMOSFET switch structure of claim 1 wherein the relative concentricity of said second driver switch means to said active load first switch means is relatively circuar circular.
Claim 10
Dependent Claim
27 words
The HVMOSFET switch structure of claim 1 wherein the relative concentricity of said driver second switch means to said active load first switch means is relatively elliptical.
References Cited (Backward Citations)
US4070653A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-07 | 1985-03-09 | 1985-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-07 | 1989-03-09 | 1989-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-07 | 1993-03-09 | 1993-09-08 | $7700.00 | Window Closed / Lapsed |