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US5962898A
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Field-effect transistor
Assignee: Texas Instruments Inc
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Filing: 1997-09-12
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Granted: 1999-10-05
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Expires: 2017-09-12
Abstract
Abstract A field-effect transistor (10, FIG. 2) possesses improved electrostatic discharge characteristics. The transistor (10), formed in a p-type semiconductor substrate, comprises a gate (16) that forms a channel between two adjacent n-regions (12 and 14). At least one of the n-regions (12) has an n-well (22) below and centered about a contact pad (18). The n-well (22) has a second lower concentration of n-type impurities than either of the n-regions.
Inventors
- 👤 Charvaka Duvvury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:03
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/124; H10D62/126; H10D1/00; H10D1/60; H10D1/62; H10D1/66; H10D30/00; H10D30/01; H10D30/021; H10D30/0221; H10D30/60; H10D30/601; H10D30/603; H10D48/00; H10D48/30; H10D48/32; H10D48/36; H10D62/13; H10D62/149; H10D62/151; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/514; H10D64/516
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
167 words
A semiconductor device comprising: a substrate having a first conductivity type; an insulating layer formed adjacent a first surface of the substrate; a gate disposed adjacent the insulating layer; first and second doped regions formed within the substrate, the first and second doped regions each having an edge adjacent the gate and the substrate and each having a first doping concentration of a second conductivity type, the second conductivity type being opposite the first conductivity type, the first and second doped regions each extending into the substrate to a first depth; a third doped region of the second conductivity type formed within the substrate, the third doped region extending into the substrate to a second depth, the second depth being greater than the first depth, the third doped region having a doping concentration less than the first doping concentration; and a first conductor directly contacting the first doped region only within a perimeter of the first doped region and within a perimeter of the third doped region.
Claim 2
Dependent Claim
167 words
A semiconductor device comprising: a substrate having a first conductivity type; an insulating layer formed adjacent a first surface of the substrate; a gate disposed adjacent the insulating layer; first and second doped regions formed within the substrate, the first and second doped regions each having an edge adjacent the gate and the substrate and each having a first doping concentration of a second conductivity type, the second conductivity type being opposite the first conductivity type, the first and second doped regions each extending into the substrate to a first depth; a third doped region of the second conductivity type formed within the substrate, the third doped region extending into the substrate to a second depth, the second depth being greater than the first depth, the third doped region having a doping concentration less than the first doping concentration; and a first conductor directly contacting the first doped region only within a perimeter of the first doped region and within a perimeter of the third doped region.
Claim 3
Dependent Claim
62 words
The device of claim 1 and further comprising: a fourth doped region extending into the substrate to the second depth, the fourth doped region having a doping concentration less than the first doping concentration; and a second conductor directly contacting the second doped region only within a perimeter of the second doped region and within a perimeter of the fourth doped region.
Claim 4
Dependent Claim
12 words
The device of claim 1 wherein the first conductivity type is p-type.
Claim 5
Dependent Claim
25 words
The device of claim 1 wherein the semiconductor device comprises a field effect transistor and wherein the first and second doped regions comprise source-drain regions.
Claim 6
Dependent Claim
19 words
The device of claim 1 wherein the second depth is five to seven times greater than the first depth.
Claim 7
Dependent Claim
16 words
The device of claim 1 wherein the substrate comprises silicon and the gate comprises polycrystalline silicon.
Claim 8
Dependent Claim
17 words
The device of claim 1, wherein the first and second doped regions are doped with arsenic dopants.
Claim 9
Dependent Claim
18 words
The device of claim 1 and further comprising field insulation regions adjacent the first and second doped regions.
Claim 10
Dependent Claim
10 words
The device of claim 8 wherein the gate comprises aluminum.
Claim 11
Dependent Claim
11 words
The device of claim 1 wherein the gate comprises a metal.
Claim 12
Dependent Claim
23 words
The device of claim 1, wherein each of the first and second doped regions comprise a double diffused region formed in the substrate.
Claim 13
Dependent Claim
234 words
A semiconductor device comprising: a substrate having a surface of a first conductivity type; an insulating layer overlying the surface of the substrate; a first elongated doped region formed at the surface of the substrate, the first elongated doped region having a first edge adjacent the substrate, the first elongated doped region having a first doping concentration of a second conductivity type, the second conductivity type being opposite the first conductivity type, the first doped region extending into the substrate to a first depth; a second elongated doped region formed at the surface of the substrate, the second elongated doped region having a second edge formed parallel to and spaced apart from the first edge, the second elongated doped region having the first doping concentration of the second conductivity type, the second doped region extending into the substrate to the first depth; a current path within the substrate between the first and second edges; a third doped region having a second doping concentration of the second conductivity type formed within the substrate, the third doped region extending into the substrate to a second depth, the second depth being greater than the first depth, the second doping concentration being less than the first doping concentration; and a first conductor directly contacting the first elongated doped region only within a perimeter of the first elongated doped region and within a perimeter of the third doped region.
Claim 14
Dependent Claim
234 words
A semiconductor device comprising: a substrate having a surface of a first conductivity type; an insulating layer overlying the surface of the substrate; a first elongated doped region formed at the surface of the substrate, the first elongated doped region having a first edge adjacent the substrate, the first elongated doped region having a first doping concentration of a second conductivity type, the second conductivity type being opposite the first conductivity type, the first doped region extending into the substrate to a first depth; a second elongated doped region formed at the surface of the substrate, the second elongated doped region having a second edge formed parallel to and spaced apart from the first edge, the second elongated doped region having the first doping concentration of the second conductivity type, the second doped region extending into the substrate to the first depth; a current path within the substrate between the first and second edges; a third doped region having a second doping concentration of the second conductivity type formed within the substrate, the third doped region extending into the substrate to a second depth, the second depth being greater than the first depth, the second doping concentration being less than the first doping concentration; and a first conductor directly contacting the first elongated doped region only within a perimeter of the first elongated doped region and within a perimeter of the third doped region.
Claim 15
Dependent Claim
24 words
A device as in claim 12, wherein the first conductor comprises a plurality of conductive regions disposed linearly and parallel to the first edge.
Claim 16
Dependent Claim
62 words
A device as in claim 12, further comprising: a fourth doped region having the second doping concentration of the second conductivity type, the fourth doped region extending into the substrate to the second depth; and a second conductor directly contacting the second doped region only within a perimeter of the second doped region and within a perimeter of the fourth doped region.
Claim 17
Dependent Claim
28 words
A device as in claim 14, wherein each of the first and second conductors comprise a plurality of conductive regions disposed linearly and parallel to the first edge.
Claim 18
Dependent Claim
18 words
A device as in claim 15, further comprising field insulation regions adjacent the first and second doped regions.
Claim 19
Dependent Claim
24 words
A device as in claim 16, wherein the first and second elongated doped regions are lightly doped source-drain regions of a field effect transistor.
Claim 20
Dependent Claim
24 words
A device as in claim 16, wherein the first and second elongated doped regions are double diffused source-drain regions of a field effect transistor.
Claim 21
Dependent Claim
12 words
A device as in claim 16, wherein the gate is polycrystalline silicon.
Claim 22
Dependent Claim
13 words
A device as in claim 12, wherein the first conductivity type is p-type.
Claim 23
Dependent Claim
14 words
A device as in claim 12, further comprising a gate overlying the current path.
Claim 24
Dependent Claim
19 words
The device of claim 12 wherein the second depth is five to seven times greater than the first depth.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-10-04 | 2003-04-05 | 2003-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-04 | 2007-04-05 | 2007-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-04 | 2011-04-05 | 2011-10-05 | $7700.00 | Window Closed / Lapsed |