US5350941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Trench isolation structure having a trench formed in a LOCOS structure and a channel stop region on the sidewalls of the trench
Assignee: Texas Instruments Inc
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Filing: 1992-09-23
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Granted: 1994-09-27
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Expires: 2012-09-23
Abstract
Abstract An isolation structure is disclosed which isolates an active region (24) from other proximate active regions. The isolation structure utilizes the combination of a LOCOS structure (26) comprising bird's beak structure (26a) and (26b). A trench (34) is formed through the LOCOS structure (26). A channel stop implant region (40) is formed along the sidewalls of the trench (34). A trench plug (46) is used to fill the trench. The isolation structure thereby uses the isolation capabilities of trench isolation structures, but prevents the leakage currents common along trench sidewalls by isolating the trench sidewalls from the active region using the LOCOS structures.
Inventors
- 👤 Sudhir K. Madan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:50
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10P; H10P50/00; H10P50/69; H10P50/691; H10P50/693; H10P50/695; H10W10/014; H10W10/0145; H10W10/0147; H10W10/041; H10W10/10; H10W10/13; H10W10/17; H10W10/40; Y; Y10; Y10S; Y10S148/00; Y10S148/05
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
129 words
An isolation structure formed in a semiconductor layer between first and second active regions in order to electrically isolate the first and second active regions one from the other, the semiconductor layer comprising an outer surface, the isolation structure comprising: a LOCOS structure formed on the outer surface, said LOCOS structure comprising a first bird's beak structure disposed laterally adjacent the first active region and a second bird's beak structure disposed laterally adjacent the second active region; a trench plug disposed in a trench formed through said LOCOS structure between said first and second bird's beak structures and in said semiconductor layer, said trench comprising sidewalls defining an interface between said trench plug and the semiconductor layer; and a channel stop region located in said sidewalls of said trench.
Claim 2
Dependent Claim
129 words
An isolation structure formed in a semiconductor layer between first and second active regions in order to electrically isolate the first and second active regions one from the other, the semiconductor layer comprising an outer surface, the isolation structure comprising: a LOCOS structure formed on the outer surface, said LOCOS structure comprising a first bird's beak structure disposed laterally adjacent the first active region and a second bird's beak structure disposed laterally adjacent the second active region; a trench plug disposed in a trench formed through said LOCOS structure between said first and second bird's beak structures and in said semiconductor layer, said trench comprising sidewalls defining an interface between said trench plug and the semiconductor layer; and a channel stop region located in said sidewalls of said trench.
Claim 3
Dependent Claim
30 words
The isolation structure of claim 1 wherein the semiconductor layer comprises a predetermined conductivity type and wherein said channel stop region comprises impurities corresponding to said first predetermined conductivity type.
Claim 4
Dependent Claim
20 words
The isolation structure of claim 1 wherein said channel stop region is formed by implanting impurities into the semiconductor layer.
Claim 5
Dependent Claim
24 words
The isolation structure of claim 1 wherein said channel stop region is formed by diffusing impurities into the semiconductor layer using solid source materials.
Claim 6
Dependent Claim
20 words
The isolation structure of claim 1 wherein the semiconductor layer comprises silicon and wherein said LOCOS structure comprises silicon dioxide.
Claim 7
Dependent Claim
12 words
The isolation structure of claim 1 wherein said trench plug comprises oxide.
Claim 8
Dependent Claim
21 words
The isolation structure of claim 1 wherein said trench plug comprises a region comprising oxide and a region comprising phosphosilicon glass.
Claim 9
Dependent Claim
21 words
The isolation structure of claim 1 wherein said trench plug comprises a region comprising oxide and a region comprising borophosphosilicon glass.
Claim 10
Dependent Claim
27 words
The isolation structure of claim 1 wherein said trench plug comprises a region of polycrystalline semiconductor material and a region comprising an oxide of said semiconductor material.
Claim 11
Dependent Claim
54 words
The isolation structure of claim 1 wherein said trench plug comprises a first trench plug formed in a first trench and further comprising a second trench plug disposed in a second trench formed through said LOCOS structure proximate said first trench between said first and second bird's beak structures and in said semiconductor layer.
Claim 12
Dependent Claim
169 words
An isolation structure formed in a semiconductor layer between first and second active regions in order to electrically isolate the first and second active regions one from the other, the semiconductor layer comprising an outer surface, the isolation structure comprising: a LOCOS structure formed on the outer surface, said LOCOS structure comprising a first bird's beak structure disposed laterally adjacent the first active region and a second bird's beak structure disposed laterally adjacent the second active region; a trench plug disposed in a trench formed through said LOCOS structure between said first and second bird's beak structures and in said semiconductor layer, said trench comprising sidewalls defining an interface between said trench plug and the semiconductor layer; and a channel stop implantation region formed in the semiconductor layer adjacent said sidewalls of said trench, the semiconductor layer comprising silicon having a predetermined conductivity type and wherein said channel stop region comprises impurities corresponding to said first predetermined conductivity type, said LOCOS structure and said trench plug comprising silicon dioxide.
Claim 13
Dependent Claim
169 words
An isolation structure formed in a semiconductor layer between first and second active regions in order to electrically isolate the first and second active regions one from the other, the semiconductor layer comprising an outer surface, the isolation structure comprising: a LOCOS structure formed on the outer surface, said LOCOS structure comprising a first bird's beak structure disposed laterally adjacent the first active region and a second bird's beak structure disposed laterally adjacent the second active region; a trench plug disposed in a trench formed through said LOCOS structure between said first and second bird's beak structures and in said semiconductor layer, said trench comprising sidewalls defining an interface between said trench plug and the semiconductor layer; and a channel stop implantation region formed in the semiconductor layer adjacent said sidewalls of said trench, the semiconductor layer comprising silicon having a predetermined conductivity type and wherein said channel stop region comprises impurities corresponding to said first predetermined conductivity type, said LOCOS structure and said trench plug comprising silicon dioxide.
Claim 14
Dependent Claim
27 words
The isolation structure of claim 11 wherein said trench plug comprises a region of polycrystalline semiconductor material and a region comprising an oxide of said semiconductor material.
Claim 15
Dependent Claim
21 words
The isolation structure of claim 11 wherein said trench plug comprises a region comprising oxide and a region comprising phosphosilicon glass.
Claim 16
Dependent Claim
21 words
The isolation structure of claim 11 wherein said trench plug comprises a region comprising oxide and a region comprising borophosphosilicon glass.
Claim 17
Dependent Claim
54 words
The isolation structure of claim 11 wherein said trench plug comprises a first trench plug formed in a first trench and further comprising a second trench plug disposed in a second trench formed through said LOCOS structure proximate said first trench between said first and second bird's beak structures and in said semiconductor layer.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-09-26 | 1998-03-28 | 1998-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-26 | 2002-03-28 | 2002-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-26 | 2006-03-28 | 2006-09-27 | $7700.00 | Window Closed / Lapsed |