US5148247A
Expired / Lapsed
US
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Semiconductor device having trench isolation
Assignee: Fujitsu Ltd
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Filing: 1991-09-05
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Granted: 1992-09-15
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Expires: 2011-09-05
Abstract
Abstract A semiconductor device having a trench isolation structure comprises a substrate, an active layer formed on the substrate, a trench which penetrates the active layer and reaches a portion of the substrate, and an insulator layer formed within the trench. The active layer has a region in which elements of the semiconductor device are formed, and the insulator layer has charges trapped in at least a predetermined portion thereof in a vicinity of the second region. This predetermined portion of the insulator layer has a depth which is greater than a depth of the region of the active layer.
Inventors
- 👤 Takao Miura
- 👤 Kazunori Imaoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:38
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0148; H10W10/041; H10W10/10; H10W10/17; H10W10/40
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
220 words
A semiconductor device having a trench isolation structure comprising: a substrate made of a first type semiconductor, said first type semiconductor being one of n-type and p-type semiconductors; an active layer formed on said substrate and also made of at least one of the first type semiconductor and a second type semiconductor, said second type semiconductor being opposite said first type semiconductor; a trench which penetrates said active layer and reaches a portion of said substrate, wherein a pn junction contacts a side surface of said trench; and an insulator layer formed within said trench and formed substantially around a peripheral portion of said trench, said active layer having a region in which elements of the semiconductor device are formed, said insulator layer penetrating, along with said trench, said active layer and a portion of said substrate, and having charges trapped in only a predetermined portion thereof in a vicinity of said region, said charges being trapped in a portion of said insulator layer which covers said pn junction at said side surface of said trench, and wherein a portion of said insulator layer above said active layer outside said trench is free from said trapped charges, said predetermined portion of said insulator layer having a depth which is greater than a depth of said region of said active layer.
Claim 2
Dependent Claim
220 words
A semiconductor device having a trench isolation structure comprising: a substrate made of a first type semiconductor, said first type semiconductor being one of n-type and p-type semiconductors; an active layer formed on said substrate and also made of at least one of the first type semiconductor and a second type semiconductor, said second type semiconductor being opposite said first type semiconductor; a trench which penetrates said active layer and reaches a portion of said substrate, wherein a pn junction contacts a side surface of said trench; and an insulator layer formed within said trench and formed substantially around a peripheral portion of said trench, said active layer having a region in which elements of the semiconductor device are formed, said insulator layer penetrating, along with said trench, said active layer and a portion of said substrate, and having charges trapped in only a predetermined portion thereof in a vicinity of said region, said charges being trapped in a portion of said insulator layer which covers said pn junction at said side surface of said trench, and wherein a portion of said insulator layer above said active layer outside said trench is free from said trapped charges, said predetermined portion of said insulator layer having a depth which is greater than a depth of said region of said active layer.
Claim 3
Dependent Claim
211 words
A semiconductor device having a trench isolation structure comprising: a substrate made of a first type semiconductor, said first type semiconductor being one of n-type and p-type semiconductors; an active layer formed on said substrate and also made of at least one of the first type semiconductor and a second type semiconductor, said second type semiconductor being opposite said first type semiconductor; a trench which penetrates said active layer and reaches a portion of said substrate, wherein a pn junction contacts a side surface of said trench; and an insulator layer formed within said trench and formed substantially around a peripheral portion of said trench, said substrate at least having a first region which is in a vicinity of a bottom portion of said trench and has an impurity density greater than that of said active layer, said active layer having a second region in which elements of the semiconductor device are formed, said insulator layer penetrating, along with said trench, said active layer and a portion of said substrate, and having charges trapped in at least a predetermined portion thereof in a vicinity of said second region, said charges being trapped in a portion of said insulator layer which covers said pn junction at said side surface of said trench.
Claim 4
Dependent Claim
211 words
A semiconductor device having a trench isolation structure comprising: a substrate made of a first type semiconductor, said first type semiconductor being one of n-type and p-type semiconductors; an active layer formed on said substrate and also made of at least one of the first type semiconductor and a second type semiconductor, said second type semiconductor being opposite said first type semiconductor; a trench which penetrates said active layer and reaches a portion of said substrate, wherein a pn junction contacts a side surface of said trench; and an insulator layer formed within said trench and formed substantially around a peripheral portion of said trench, said substrate at least having a first region which is in a vicinity of a bottom portion of said trench and has an impurity density greater than that of said active layer, said active layer having a second region in which elements of the semiconductor device are formed, said insulator layer penetrating, along with said trench, said active layer and a portion of said substrate, and having charges trapped in at least a predetermined portion thereof in a vicinity of said second region, said charges being trapped in a portion of said insulator layer which covers said pn junction at said side surface of said trench.
Claim 5
Dependent Claim
34 words
A semiconductor device as claimed in claim 2 in which said predetermined portion of said insulator layer has a depth which is greater than a depth of said second region of said active layer.
Claim 6
Dependent Claim
42 words
A semiconductor device as claimed in claim 3 in which said active layer comprises said second region and a depletion region located immediately under said second region, said first region extending from a depth greater than a depth of said depletion region.
Claim 7
Dependent Claim
51 words
A semiconductor device as claimed in claim 3 in which said active layer comprises said second region and a depletion region located immediately under said second region, said first region extending from a depth greater than the depth of said second region and less than a depth of said depletion region.
Claim 8
Dependent Claim
43 words
A semiconductor device as claimed in claim 3 in which said active layer comprises said second region and a depletion region located immediately under said second region, said first region extending from a depth approximately coinciding with the depth of said second region.
Claim 9
Dependent Claim
23 words
A semiconductor device as claimed in claim 2 in which said insulator layer is formed on all of inner walls of said trench.
Claim 10
Dependent Claim
28 words
A semiconductor device as claimed in claim 2 in which said insulator layer is formed on all of inner walls of said trench excluding a bottom portion thereof.
Claim 11
Dependent Claim
20 words
A semiconductor device as claimed in claim 2 in which said insulator layer has the charges trapped in its entirety.
Claim 12
Dependent Claim
21 words
A semiconductor device as claimed in claim 2 which further comprises another insulator layer which fills an inside of said trench.
Claim 13
Dependent Claim
30 words
A semiconductor device as claimed in claim 2 in which said first type semiconductor is a p-type semiconductor, and said second region of said active layer is an n-type region.
Claim 14
Dependent Claim
24 words
A semiconductor device as claimed in claim 11 in which said insulator layer has negative charges trapped in at least said predetermined portion thereof.
Claim 15
Dependent Claim
21 words
A semiconductor device as claimed in claim 11 in which said insulator layer is an oxide layer formed within said trench.
Claim 16
Dependent Claim
51 words
A semiconductor device as claimed in claim 2 in which said substrate is made of a heavily doped first type semiconductor and said active layer is an epitaxial layer made of a lightly doped first type semiconductor having an impurity concentration less than that of said heavily doped first type semiconductor.
Claim 17
Dependent Claim
22 words
A semiconductor device as claimed in claim 14 in which said first region of said substrate is constituted by said substrate itself.
Claim 18
Dependent Claim
30 words
A semiconductor device as claimed in claim 14 in which said first type semiconductor is a p-type semiconductor, and said second region of said active layer is an n-type region.
Claim 19
Dependent Claim
24 words
A semiconductor device as claimed in claim 14 in which said insulator layer has negative charges trapped in at least said predetermined portion thereof.
Claim 20
Dependent Claim
21 words
A semiconductor device as claimed in claim 14 in which said insulator layer is an oxide layer formed within said trench.
Claim 21
Dependent Claim
32 words
A semiconductor device as claimed in claim 2 in which said second region of said active layer is a region in which drain and source of a field effect transistor are formed.
Claim 22
Dependent Claim
43 words
A semiconductor device as claimed in claim 2 in which said insulator layer is formed on all of inner walls of said trench excluding a bottom portion thereof, and said bottom portion having formed thereon another insulator layer having no charges trapped therein.
Claim 23
Dependent Claim
217 words
A semiconductor device having a trench isolation structure comprising: a substrate made of a first type semiconductor, said first type semiconductor being one of n-type and p-type semiconductors; an active layer formed on said substrate and also made of the first type semiconductor; a trench which penetrates said active layer and reaches a portion of said substrate; and an insulator layer formed within said trench and formed substantially around a peripheral portion of said trench, said substrate at least having a first region which is in a vicinity of a bottom portion of said trench and has an impurity density greater than that of said active layer, said active layer having a second region in which elements of the semiconductor device are formed, wherein said active layer comprises said second region and a depletion region located immediately under said second region, said first region extending from a depth approximately coinciding with the depth of said second region, said insulator layer penetrating, along with said trench, said active layer and a portion of said substrate, and having charges trapped in at least a predetermined portion thereof in a vicinity of said second region, wherein said predetermined portion of said insulator layer has a depth which is greater than a depth of said second region of said active layer.
Claim 24
Dependent Claim
217 words
A semiconductor device having a trench isolation structure comprising: a substrate made of a first type semiconductor, said first type semiconductor being one of n-type and p-type semiconductors; an active layer formed on said substrate and also made of the first type semiconductor; a trench which penetrates said active layer and reaches a portion of said substrate; and an insulator layer formed within said trench and formed substantially around a peripheral portion of said trench, said substrate at least having a first region which is in a vicinity of a bottom portion of said trench and has an impurity density greater than that of said active layer, said active layer having a second region in which elements of the semiconductor device are formed, wherein said active layer comprises said second region and a depletion region located immediately under said second region, said first region extending from a depth approximately coinciding with the depth of said second region, said insulator layer penetrating, along with said trench, said active layer and a portion of said substrate, and having charges trapped in at least a predetermined portion thereof in a vicinity of said second region, wherein said predetermined portion of said insulator layer has a depth which is greater than a depth of said second region of said active layer.
Claim 25
Dependent Claim
169 words
A semiconductor device having a trench isolation structure comprising: a substrate made of a first type semiconductor, said first type semiconductor being one of n-type and p-type semiconductors; an active layer formed on said substrate and also made of the first type semiconductor; a trench which penetrates said active layer and reaches a portion of said substrate; and an insulator layer formed within said trench and formed substantially around a peripheral portion of said trench, said substrate at least having a first region which is in a vicinity of a bottom portion of said trench and has an impurity density greater than that of said active layer, said active layer having a second region in which elements of the semiconductor device are formed, said insulator layer penetrating, along with said trench, said active layer and a portion of said substrate, and having charges trapped in at least a predetermined portion thereof in a vicinity of said second region, wherein said insulator layer has said charges trapped in its entirety.
Claim 26
Dependent Claim
169 words
A semiconductor device having a trench isolation structure comprising: a substrate made of a first type semiconductor, said first type semiconductor being one of n-type and p-type semiconductors; an active layer formed on said substrate and also made of the first type semiconductor; a trench which penetrates said active layer and reaches a portion of said substrate; and an insulator layer formed within said trench and formed substantially around a peripheral portion of said trench, said substrate at least having a first region which is in a vicinity of a bottom portion of said trench and has an impurity density greater than that of said active layer, said active layer having a second region in which elements of the semiconductor device are formed, said insulator layer penetrating, along with said trench, said active layer and a portion of said substrate, and having charges trapped in at least a predetermined portion thereof in a vicinity of said second region, wherein said insulator layer has said charges trapped in its entirety.
Claim 27
Dependent Claim
28 words
A semiconductor device as claimed in claim 2 wherein a portion of said insulator layer above said active layer outside said trench is free from said trapped charges.
References Cited (Backward Citations)
US3463974A
Cited
US3787251A
Cited
JPS57159030A
Cited
US4755863A
Cited
JPS6043843A
Cited
JPS6158266A
Cited
EP0177066A2
Cited
JPS61154160A
Cited
JPS62113467A
Cited
EP0245783A2
Cited
US4866494A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-15 | 1996-03-16 | 1996-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-15 | 2000-03-16 | 2000-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-15 | 2004-03-16 | 2004-09-15 | $7700.00 | Window Closed / Lapsed |