US5905286A
Expired / Lapsed
US
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Semiconductor device
Assignee: Renesas Electronics Corp
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Filing: 1997-02-04
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Granted: 1999-05-18
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Expires: 2017-02-04
Abstract
Abstract In a semiconductor device having an SOI structure and a method of manufacturing the same, influence by a parasitic transistor can be prevented, and no disadvantage is caused in connection with a manufacturing process. In this semiconductor device, an upper side portion of a semiconductor layer is rounded. Thereby, concentration of an electric field at the upper side portion of the semiconductor layer can be prevented. As a result, lowering of a threshold voltage of a parasitic transistor can be prevented, so that the parasitic transistor does not adversely affect subthreshold characteristics of a regular transistor. Owing to provision of a concavity of a U-shaped section, generation of etching residue can be prevented when etching a gate electrode for patterning the same. Thereby, a disadvantage is not caused in connection with the manufacturing process.
Inventors
- 👤 Toshiaki Iwamatsu
- 👤 Yasuo Yamaguchi
- 👤 Shigenobu Maeda
- 👤 Shoichi Miyamoto
- 👤 Akihiko Furukawa
- 👤 Yasuo Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:35
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0321; H10D30/0323; H10D30/60; H10D30/67; H10D30/6704; H10D30/6708; H10D30/6723; H10D30/674; H10D30/6741; H10D30/6743; H10D30/6744; H10D86/00; H10D86/01; H10D86/201; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/019; H10W10/021; H10W10/10; H10W10/20; H10P; H10P30/00; H10P30/20; H10P30/22; H10P30/221; H10P30/222
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
50 words
A semiconductor device comprising: a semiconductor layer formed on a predetermined region of an insulating layer and having a main surface; and a field-effect transistor formed on the main surface of said semiconductor layer, wherein said semiconductor layer has a concave round section at an end of its main surface.
Claim 2
Dependent Claim
50 words
A semiconductor device comprising: a semiconductor layer formed on a predetermined region of an insulating layer and having a main surface; and a field-effect transistor formed on the main surface of said semiconductor layer, wherein said semiconductor layer has a concave round section at an end of its main surface.
Claim 3
Dependent Claim
49 words
The semiconductor device according to claim 1, further comprising an impurity region formed at a side surface of said semiconductor layer, wherein said insulating layer under said semiconductor layer has a U-shaped concavity at a region located near a lower end of the side surface of said impurity region.
Claim 4
Dependent Claim
51 words
The semiconductor device according to claim 2, wherein said lower end of the side surface of said impurity region extends substantially perpendicularly to the main surface of said insulating layer; and said concavity of said insulating layer is continuous with said lower end of the side surface of said impurity region.
Claim 5
Dependent Claim
47 words
The semiconductor device according to claim 2, further comprising: a first side wall insulating film formed in contact with the side surface of said impurity region; and a second side wall insulating film formed in contact with a side surface of said first side wall insulating film.
Claim 6
Dependent Claim
35 words
The semiconductor device according to claim 2, wherein: said impurity region has the same conductivity type as said semiconductor layer; and said impurity region has an impurity concentration greater than that of said semiconductor layer.
Claim 7
Dependent Claim
21 words
The semiconductor device according to claim 1, further comprising an impurity region formed at a side surface of said semiconductor layer.
Claim 8
Dependent Claim
26 words
The semiconductor device according to claim 6, wherein the side surface of the impurity region is substantially perpendicular to the main surface of said semiconductor layer.
Claim 9
Dependent Claim
37 words
The semiconductor device according to claim 6, wherein: said impurity region has the same conductivity type as that of said semiconductor layer; and said impurity region has an impurity concentration greater than that of said semiconductor layer.
Claim 10
Dependent Claim
23 words
The semiconductor device according to claim 1, further comprising first and second insulating films formed on a side surface of said semiconductor layer.
Claim 11
Dependent Claim
98 words
A semiconductor device comprising: a semiconductor layer formed at a predetermined region on an insulating layer, which has a U-shaped concavity, said semiconductor layer having a main surface; an impurity region formed at a side surface of said semiconductor layer; and a field-effect transistor formed at the main surface of said semiconductor layer; wherein said impurity region has a round section formed in an upper part of said impurity region, wherein: said impurity region has the same conductivity type as said semiconductor layer; and said impurity region has an impurity concentration greater than that of said semiconductor layer.
Claim 12
Dependent Claim
98 words
A semiconductor device comprising: a semiconductor layer formed at a predetermined region on an insulating layer, which has a U-shaped concavity, said semiconductor layer having a main surface; an impurity region formed at a side surface of said semiconductor layer; and a field-effect transistor formed at the main surface of said semiconductor layer; wherein said impurity region has a round section formed in an upper part of said impurity region, wherein: said impurity region has the same conductivity type as said semiconductor layer; and said impurity region has an impurity concentration greater than that of said semiconductor layer.
Claim 13
Dependent Claim
40 words
A semiconductor device comprising: a semiconductor layer having a main surface; and a field-effect transistor formed on the main surface or said semiconductor layer, wherein said semiconductor layer has a concave round section at an end of its main surface.
Claim 14
Dependent Claim
40 words
A semiconductor device comprising: a semiconductor layer having a main surface; and a field-effect transistor formed on the main surface or said semiconductor layer, wherein said semiconductor layer has a concave round section at an end of its main surface.
Claim 15
Dependent Claim
21 words
The semiconductor device according to claim 11, further comprising an impurity region formed at a side surface of said semiconductor layer.
Claim 16
Dependent Claim
26 words
The semiconductor device according to claim 12, wherein the side surface of the impurity region is substantially perpendicular to the main surface of said semiconductor layer.
Claim 17
Dependent Claim
37 words
The semiconductor device according to claim 12, wherein: said impurity region has the same conductivity type as that of said semiconductor layer; and said impurity region has an impurity concentration greater than that of said semiconductor layer.
Claim 18
Dependent Claim
22 words
The semiconductor device according to claim 11, further-comprising first and second insulating films formed on a side surface of said semiconductor layer.
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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) | 2002-05-17 | 2002-11-16 | 2003-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-05-17 | 2006-11-16 | 2007-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-05-17 | 2010-11-16 | 2011-05-18 | $7700.00 | Window Closed / Lapsed |