Patent US4962365A successfully refreshed from Google Patents.
US4962365A
Expired / Lapsed
US
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Integrated circuit trench resistor
Assignee: Texas Instruments Inc
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Filing: 1989-03-30
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Granted: 1990-10-09
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Expires: 2009-03-30
Abstract
Abstract A resistor (10) includes a resistive filling (28) formed within a trench (12) and separated therefrom by an insulating layer (26). Resistive filling (28) is of the same type of semiconductor material as that of second layer (22), but of an opposite extreme of dopant concentration. A head region (32) may be formed below interface (30) within second layer (22) to more clearly delineate the edge of resistive filling (28) from second layer (22). Where resistive filling (28) is of a low dopant concentration, low resistance contact region (34) is formed of a high dopant concentration in order to provide a minimum resistance contact to resistive filling (28).
Inventors
- 👤 Robert H. Havemann
- 👤 Robert H. Eklund
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:31
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/201; H10D84/204; H10D84/209; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
106 words
A resistor formed in an integrated circuit comprising: a substrate having a first conductivity type; a trench formed in said substrate extending from a surface of said substrate into said substrate; an insulating layer formed on the sidewalls of said trench; a buried doped region formed in said substrate at the bottom of said trench, said buried doped region being spaced from said surface and said buried dope region having a second conductivity type opposite to said first conductivity type; a resistive filling filling the remainder of said trench and providing a resistive electrical connection between said buried doped region and the surface of said substrate.
Claim 2
Dependent Claim
106 words
A resistor formed in an integrated circuit comprising: a substrate having a first conductivity type; a trench formed in said substrate extending from a surface of said substrate into said substrate; an insulating layer formed on the sidewalls of said trench; a buried doped region formed in said substrate at the bottom of said trench, said buried doped region being spaced from said surface and said buried dope region having a second conductivity type opposite to said first conductivity type; a resistive filling filling the remainder of said trench and providing a resistive electrical connection between said buried doped region and the surface of said substrate.
Claim 3
Dependent Claim
13 words
A resistor as in claim 1 wherein said resistive material comprises polycrystalline silicon.
Claim 4
Dependent Claim
14 words
A resistor as in claim 2 wherein said polycrystalline silicon is doped polycrystalline silicon.
Claim 5
Dependent Claim
19 words
A resistor as in claim 3 wherein the conductivity type of said polycrystalline silicon is said second conductivity type.
Claim 6
Dependent Claim
13 words
A resistor as in claim 1 wherein said resistive material comprises crystalline silicon.
Claim 7
Dependent Claim
14 words
A resistor as in claim 5 wherein said crystalline silicon is doped crystalline silicon.
Claim 8
Dependent Claim
19 words
A resistor as in claim 6 wherein the conductivity type of said crystalline silicon is said second conductivity type.
Claim 9
Dependent Claim
34 words
A resistor as in claim 1 wherein the portion of said buried doped region adjacent to said resistive filling is doped to a higher conductivity level than the remainder of said buried doped region.
Claim 10
Dependent Claim
22 words
A resistor as in claim 1 further comprising a silicided region formed at the end of said resistive filing nearest said surface.
Claim 11
Dependent Claim
12 words
A resistor as in claim 1 wherein said insulating layer is silicon-dioxide.
Claim 12
Dependent Claim
12 words
A resistor as in claim 1 wherein said substrate comprises crystalline silicon.
References Cited (Backward Citations)
US4782030A
Cited
US4728623A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-08 | 1994-04-09 | 1994-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-08 | 1998-04-09 | 1998-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-08 | 2002-04-09 | 2002-10-09 | $7700.00 | Window Closed / Lapsed |