Patent US5539238A successfully refreshed from Google Patents.
US5539238A
Expired / Lapsed
US
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Area efficient high voltage Mosfets with vertical resurf drift regions
Assignee: Texas Instruments Inc
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Filing: 1992-09-02
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Granted: 1996-07-23
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Expires: 2012-09-02
Abstract
Abstract A high voltage power transistor cell is developed that provides improved RDSon performance without sacrificing breakdown performance through utilization of trench based transistor technology. A source, drain and trench are formed within a substrate. A gate is formed on the surface over a spacing between the source and the trench. A drift region is formed around the trench. An isolation region may optionally be added allowing electrical isolation between the source and the substrate. The lateral current flow feature allows multiple high voltage power transistors, electrically isolated from one another, to exist on a single semiconductor chip. The drift region formed around the trench provides RESURF transistor characteristics without sacrificing die area.
Inventors
- 👤 Satwinder Malhi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:09
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/601; H10D30/603; H10D30/01; H10D30/021; H10D30/0221; H10D30/608; H10D30/64; H10D30/65; H10D30/66; H10D30/663; H10D62/00; H10D62/01; H10D62/021; H10D62/10; H10D62/102; H10D62/103; H10D62/105; H10D62/113; H10D62/115; H10D62/116; H10D62/13; H10D62/149; H10D62/151; H10D64/00; H10D64/20; H10D64/23; H10D64/251; H10D64/256; H10P; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/141; H10P32/17; H10P32/171; Y; Y10; Y10S; Y10S148/00; Y10S148/126
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
22 words
A lateral power transistor, comprising: source; gate; drain; trench disposed between the gate and the drain; and drift region surrounding the trench.
Claim 2
Dependent Claim
22 words
A lateral power transistor, comprising: source; gate; drain; trench disposed between the gate and the drain; and drift region surrounding the trench.
Claim 3
Dependent Claim
14 words
The lateral power transistor of claim 1 further comprising an insulator filling the trench.
Claim 4
Dependent Claim
11 words
The lateral power transistor claim 2 wherein the insulator is oxide.
Claim 5
Dependent Claim
27 words
The lateral power transistor of claim 1 wherein the source and drain are composed of N type semiconductor material and the gate is composed of polycrystalline silicon.
Claim 6
Dependent Claim
53 words
A power transistor, comprising: a substrate; a body region formed in the substrate; a source region formed in the body; a gate; a drain region formed in the substrate; a trench formed in the face of the substrate between the source region and the drain region; and a drift region encircling the trench.
Claim 7
Dependent Claim
53 words
A power transistor, comprising: a substrate; a body region formed in the substrate; a source region formed in the body; a gate; a drain region formed in the substrate; a trench formed in the face of the substrate between the source region and the drain region; and a drift region encircling the trench.
Claim 8
Dependent Claim
31 words
The power transistor of claim 5 further comprising an isolation region formed in the face of the substrate below the body region to electrically isolate the source region from the substrate.
Claim 9
Dependent Claim
49 words
The high voltage power transistor cell of claim 5 wherein the substrate doping concentration and the drift region depth and doping profile are designed according to RESURF transistor design principles such that the drift region fully depletes at or before rated breakdown voltage of the high voltage power transistor.
References Cited (Backward Citations)
JPS61141180A
Cited
JPH01125971A
Cited
JPH01162373A
Cited
JPH01187870A
Cited
JPH0258378A
Cited
JPH02119184A
Cited
JPH02125667A
Cited
JPH0366166A
Cited
JPH03190278A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-07-23 | 2000-01-22 | 2000-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-23 | 2004-01-22 | 2004-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-23 | 2008-01-22 | 2008-07-23 | $7700.00 | Window Closed / Lapsed |