Patent US4905072A successfully refreshed from Google Patents.
US4905072A
Expired / Lapsed
US
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Semiconductor element
Assignee: Canon Inc
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Filing: 1988-04-29
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Granted: 1990-02-27
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Expires: 2008-04-29
Abstract
Abstract A semiconductor device comprises a semiconductor layer of a polycrystalline silicon thin film containing not more than 3 atomic % hydrogen atoms and having a surface unevenness of not more than 800 ANGSTROM at its maximum. It may also have an etching rate of 20 ANGSTROM /sec. when etched with a mixture of HF, HNO3 and glacial acetic acid (1:3:6).
Inventors
- 👤 Toshiyuki Komatsu
- 👤 Yutaka Hirai
- 👤 Katsumi Nakagawa
- 👤 Yoshiyuki Osada
- 👤 Satoshi Omata
- 👤 Takashi Nakagiri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:44
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/40; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
69 words
A semiconductor device which comprises a substrate and a semiconductor layer of a polycrystalline silicon thin film formed on the substrate, said film containing hydrogen atoms in an amount of not more than 3 atomic % and having a surface unevenness of substantially not more than 800 Å at its maximum, and said semiconductor layer of a polycrystalline silicon thin film constituting the main part of the semiconductor device.
Claim 2
Dependent Claim
69 words
A semiconductor device which comprises a substrate and a semiconductor layer of a polycrystalline silicon thin film formed on the substrate, said film containing hydrogen atoms in an amount of not more than 3 atomic % and having a surface unevenness of substantially not more than 800 Å at its maximum, and said semiconductor layer of a polycrystalline silicon thin film constituting the main part of the semiconductor device.
Claim 3
Dependent Claim
93 words
A semiconductor device which comprises a semiconductor layer of a polycrystalline silicon thin film containing hydrogen atoms in an amount of not more than 3 atomic % and having an etching rate of 20 Å/sec or less by etching with an etchant comprising a mixture of hydrofluoric acid (50 vol. % aqueous solution), nitric acid ( d =1.38, 60 vol. % aqueous solution) and glacial acetic acid at a mixing ratio by volume of 1:3:6, and said semiconductor layer of a polycrystalline silicon thin film constituting the main part of the semiconductor device.
Claim 4
Dependent Claim
93 words
A semiconductor device which comprises a semiconductor layer of a polycrystalline silicon thin film containing hydrogen atoms in an amount of not more than 3 atomic % and having an etching rate of 20 Å/sec or less by etching with an etchant comprising a mixture of hydrofluoric acid (50 vol. % aqueous solution), nitric acid ( d =1.38, 60 vol. % aqueous solution) and glacial acetic acid at a mixing ratio by volume of 1:3:6, and said semiconductor layer of a polycrystalline silicon thin film constituting the main part of the semiconductor device.
Claim 5
Dependent Claim
110 words
A semiconductor device which comprises a semiconductor layer of a polycrystalline silicon thin film containing hydrogen atoms in an amount of not more than 3 atomic % having a surface unevenness of substantially not more than 800 Å at its maximum and having an etching rate of 20 Å/sec. or less by ethhing with an etchant comprising a mixture of hydrofluoric acid (50 vol. % aqueous solution), nitric acid (d =1.38, 60 vol. % aqueous solution) and glacial acetic acid at a mixing ratio by volume of 1 : 3 : 6 and said semiconductor layer of a polycrystalline silicon thin film constituting the main part of the semiconductor device.
Claim 6
Dependent Claim
110 words
A semiconductor device which comprises a semiconductor layer of a polycrystalline silicon thin film containing hydrogen atoms in an amount of not more than 3 atomic % having a surface unevenness of substantially not more than 800 Å at its maximum and having an etching rate of 20 Å/sec. or less by ethhing with an etchant comprising a mixture of hydrofluoric acid (50 vol. % aqueous solution), nitric acid (d =1.38, 60 vol. % aqueous solution) and glacial acetic acid at a mixing ratio by volume of 1 : 3 : 6 and said semiconductor layer of a polycrystalline silicon thin film constituting the main part of the semiconductor device.
Claim 7
Dependent Claim
42 words
A semiconductor device according to claim 1, wherein said semiconductor layer has an X-ray diffraction pattern or an electron beam diffraction pattern, of which the orientation strength at the (220) plane is 30 % or more based on the total orientation strength.
Claim 8
Dependent Claim
42 words
A semiconductor device according to claim 2, wherein said semiconductor layer has an X-ray diffraction pattern or an electron beam diffraction pattern, of which the orientation strength at the (220) plane is 30 % or more based on the total orientation strength.
Claim 9
Dependent Claim
42 words
A semiconductor device according to claim 3, wherein said semiconductor layer has an X-ray diffraction pattern or an electron beam diffraction pattern, of which the orientation strength at the (220) plane is 30 % or more based on the total orientation strength.
Claim 10
Dependent Claim
23 words
A semiconductor device according to claim 1, wherein said semiconductor layer contains crystals with an average particle size of 200 Å or larger.
Claim 11
Dependent Claim
23 words
A semiconductor device according to claim 2, wherein said semiconductor layer contains crystals with an average particle size of 200 Å or larger.
Claim 12
Dependent Claim
23 words
A semiconductor device according to claim 3, wherein said semiconductor layer contains crystals with an average particle size of 200 Å or larger.
Claim 13
Dependent Claim
13 words
A semiconductor device according to claim 1, wherein said substrate is a glass.
References Cited (Backward Citations)
US3519901A
Cited
US4409605A
Cited
US4176365A
Cited
US4701394A
Cited
US4719501A
Cited
US4766477A
Cited
US4740829A
Cited
US4737429A
Cited
US4741964A
Cited
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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) | 1993-02-26 | 1993-08-28 | 1994-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-26 | 1997-08-28 | 1998-02-27 | $3760.00 | Window Closed / Lapsed |
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