US5274262A
Expired / Lapsed
US
⏱️ 0.0 years remaining
SCR protection structure and circuit with reduced trigger voltage
Assignee: Sofics Bvba
•
Filing: 1991-12-09
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Granted: 1993-12-28
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Expires: 2011-12-09
Abstract
Abstract A low breakdown voltage device for protecting an integrated circuit from transient energy is disclosed. This device provides an SCR having a reduced "snap-back" trigger voltage compatible with submicron integrated circuit fabrication processes. A low breakdown voltage SCR protection circuit is also disclosed.
Inventors
- 👤 Leslie R. Avery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:25
CPC Classifications
H; H10; H10D; H10D89/00; H10D89/60; H10D89/601; H10D89/711; H10D89/713; H02; H02H; H02H9/00; H02H9/04; H02H9/045; H02H9/046
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
234 words
A protection device comprising: a semiconductor substrate of a first conductivity type having a surface; a first region of second conductivity type in said substrate at said surface and having a boundary with said substrate; a second region of said second conductivity type within said first region and at said substrate surface; a third region of said first conductivity type within said first region at said substrate surface and adjacent said second region; a fourth region, which is of higher conductivity than the first region, in said first region at said substrate surface and extending across the boundary with the substrate into said substrate along said surface; a fifth region of said second conductivity type in said substrate at said surface and spaced apart from said first region; a sixth region of said first conductivity type in said substrate at said surface and spaced apart from said first region; a seventh region of opposite conductivity type to the fourth region and abutting the fourth region; a first terminal in electrical contact with both said second and third regions; and a second terminal in electrical contact with both said fifth and sixth regions; said substrate, first region and fifth region forming a first bipolar transistor of one conductivity type, and said substrate, first region and third region forming a second bipolar transistor of the opposite conductivity type which is connected to the first bipolar transistor.
Claim 2
Dependent Claim
234 words
A protection device comprising: a semiconductor substrate of a first conductivity type having a surface; a first region of second conductivity type in said substrate at said surface and having a boundary with said substrate; a second region of said second conductivity type within said first region and at said substrate surface; a third region of said first conductivity type within said first region at said substrate surface and adjacent said second region; a fourth region, which is of higher conductivity than the first region, in said first region at said substrate surface and extending across the boundary with the substrate into said substrate along said surface; a fifth region of said second conductivity type in said substrate at said surface and spaced apart from said first region; a sixth region of said first conductivity type in said substrate at said surface and spaced apart from said first region; a seventh region of opposite conductivity type to the fourth region and abutting the fourth region; a first terminal in electrical contact with both said second and third regions; and a second terminal in electrical contact with both said fifth and sixth regions; said substrate, first region and fifth region forming a first bipolar transistor of one conductivity type, and said substrate, first region and third region forming a second bipolar transistor of the opposite conductivity type which is connected to the first bipolar transistor.
Claim 3
Dependent Claim
19 words
The device of claim 1 wherein said seventh region extends a distance into said first region from said surface.
Claim 4
Dependent Claim
18 words
The device of claim 2 wherein said seventh region has the same conductivity type as said first region.
Claim 5
Dependent Claim
18 words
The device of claim 1 wherein said seventh region extends a distance into said substrate from said surface.
Claim 6
Dependent Claim
17 words
The device of claim 4 wherein said seventh region has the same conductivity type as said substrate.
Claim 7
Dependent Claim
15 words
The device of claim 1 wherein said fourth region is of said first conductivity type.
Claim 8
Dependent Claim
19 words
The device of claim 6 wherein said seventh region extends a distance into said first region from said surface.
Claim 9
Dependent Claim
15 words
The device of claim 1 wherein said fourth region is of said second conductivity type.
Claim 10
Dependent Claim
18 words
The device of claim 8 wherein said seventh region extends a distance into said substrate from said surface.
Claim 11
Dependent Claim
262 words
A structure comprising: an integrated circuit having first and second terminals and a reference terminal; a SCR protection device having first and second electrodes, each electrode being connected to one of said terminals; wherein said protection device comprises: a semiconductor substrate of a first conductivity type having a surface; a first region of second conductivity type in said substrate at said surface and having a boundary with said substrate; a second region of said second conductivity type within said first region at said substrate surface; a third region, of said first conductivity type within said first region at said substrate surface and adjacent said second region; a fourth region, which is of higher conductivity than said first region in said first region and extending across the boundary with the substrate into said substrate; a fifth region of said second conductivity type in said substrate at said surface outside the boundary of said first region; a sixth region of said first conductivity type in said substrate at said surface outside the boundary of said first region; and a seventh region of opposite conductivity type to the fourth region and abutting the fourth region; wherein the first electrode is in electrical contact with the second and third regions and the second electrode is in electrical contact with the fifth and sixth regions; the substrate, first region and fifth region forming a first bipolar transistor of one conductivity type, and the substrate, first region and third region forming a second bipolar transistor of the opposite conductivity type which is connected to the first bipolar transistor.
Claim 12
Dependent Claim
262 words
A structure comprising: an integrated circuit having first and second terminals and a reference terminal; a SCR protection device having first and second electrodes, each electrode being connected to one of said terminals; wherein said protection device comprises: a semiconductor substrate of a first conductivity type having a surface; a first region of second conductivity type in said substrate at said surface and having a boundary with said substrate; a second region of said second conductivity type within said first region at said substrate surface; a third region, of said first conductivity type within said first region at said substrate surface and adjacent said second region; a fourth region, which is of higher conductivity than said first region in said first region and extending across the boundary with the substrate into said substrate; a fifth region of said second conductivity type in said substrate at said surface outside the boundary of said first region; a sixth region of said first conductivity type in said substrate at said surface outside the boundary of said first region; and a seventh region of opposite conductivity type to the fourth region and abutting the fourth region; wherein the first electrode is in electrical contact with the second and third regions and the second electrode is in electrical contact with the fifth and sixth regions; the substrate, first region and fifth region forming a first bipolar transistor of one conductivity type, and the substrate, first region and third region forming a second bipolar transistor of the opposite conductivity type which is connected to the first bipolar transistor.
Claim 13
Dependent Claim
19 words
The device of claim 10 wherein said seventh region extends a distance into said first region from said surface.
Claim 14
Dependent Claim
18 words
The device of claim 11 wherein said seventh region has the same conductivity type as said first region.
Claim 15
Dependent Claim
18 words
The device of claim 10 wherein said seventh region extends a distance into said substrate from said surface.
Claim 16
Dependent Claim
17 words
The device of claim 13 wherein said seventh region has the same conductivity type as said substrate.
Claim 17
Dependent Claim
15 words
The structure of claim 10 wherein said fourth region is of said first conductivity type.
Claim 18
Dependent Claim
15 words
The structure of claim 10 wherein said fourth region is of said second conductivity type.
Claim 19
Dependent Claim
18 words
The structure of claim 10 wherein said second terminal is an input signal terminal of said integrated circuit.
Claim 20
Dependent Claim
18 words
The structure of claim 10 wherein said second terminal is an output signal terminal of said integrated circuit.
Claim 21
Dependent Claim
18 words
The structure of claim 10 wherein said second terminal is a voltage supply terminal of said integrated circuit.
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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) | 1996-12-27 | 1997-06-28 | 1997-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-12-27 | 2001-06-28 | 2001-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-12-27 | 2005-06-28 | 2005-12-28 | $7700.00 | Window Closed / Lapsed |