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Patent US4921026A successfully refreshed from Google Patents.
US4921026A
Expired / Lapsed
US
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Polycrystalline silicon capable of yielding long lifetime single crystalline silicon
Assignee: Advanced Silicon Materials LLC
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Filing: 1988-06-01
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Granted: 1990-05-01
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Expires: 2008-06-01
Abstract
Abstract Polycrystalline silicon rod capable of providing within no more than two floating zoning passes, unicrystalline silicon exhibiting a resistivity of at least 10,000 ohm-cm (donor) and a lifetime of at least about 10,000 milliseconds, exhibits a copper X-ray diffraction pattern having a peak at 26.85°±0.25° (2 theta) and has less than 15 ppta boron and less than 20 ppta phosphorus.
Inventors
- 👤 Robert N. Flagella
- 👤 Howard J. Dawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:35
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/02; C30; C30B; C30B29/00; C30B29/02; C30B29/06; C01B33/021; C01B33/027; C01B33/035; C30B13/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
120 words
Polycrystalline silicon rod which is capable of providing within no more than two float zoning passes, unicrystalline silicon exhibiting a resistively of at least 10,000 ohm-cm (donor) and a lifetime of at least about 10,000 microseconds, said polycrystalline silicon rod comprising any starter filament used in its manufacture and a polycrystalline growth layer; said rod having a diameter of at least about 50 millimeters and length of at least about 0.5 meters; said polycrystalline silicon growth layer exhibiting an X-ray powder diffraction pattern (copper radiation) having a peak at 26.85±0.25° (2 theta) which is at least about 1.75 percent of the (111) peak and said polycrystalline silicon rod containing less than 15 ppta boron and less than 20 ppta phosphorus.
Claim 2
Dependent Claim
120 words
Polycrystalline silicon rod which is capable of providing within no more than two float zoning passes, unicrystalline silicon exhibiting a resistively of at least 10,000 ohm-cm (donor) and a lifetime of at least about 10,000 microseconds, said polycrystalline silicon rod comprising any starter filament used in its manufacture and a polycrystalline growth layer; said rod having a diameter of at least about 50 millimeters and length of at least about 0.5 meters; said polycrystalline silicon growth layer exhibiting an X-ray powder diffraction pattern (copper radiation) having a peak at 26.85±0.25° (2 theta) which is at least about 1.75 percent of the (111) peak and said polycrystalline silicon rod containing less than 15 ppta boron and less than 20 ppta phosphorus.
Claim 3
Dependent Claim
34 words
The polycrystalline silicon rod of claim 1 in which the polycrystalline silicon growth layer exhibits a full width at half maximum copper X-ray powder diffraction pattern for the (111) peak of at least 0.27°.
Claim 4
Dependent Claim
16 words
The polycrystalline silicon rod of claim 2 which is prepared by the thermal decomposition of silane.
Claim 5
Dependent Claim
30 words
The polycrystalline silicon rod of claim 2 in which the full width at half maximum of the (111) peak of the copper X-ray diffraction pattern is about 0.30° to 0.50°.
Claim 6
Dependent Claim
28 words
The polycrystalline silicon rod of claim 2 in which the polycrystalline structure of the growth layer is oriented in a direction parallel to the axis of the rod.
Claim 7
Dependent Claim
14 words
The polycrystalline silicon rod of claim 1 which contains less than 5 ppta aluminum.
Claim 8
Dependent Claim
14 words
The polycrystalline silicon rod of claim 1 which contains less than 0.1 ppma carbon.
Claim 9
Dependent Claim
25 words
The polycrystalline silicon rod of claim 1 which contains a starter filament comprising silicon and having a diameter of between about 2 and 10 millimeters.
Claim 10
Dependent Claim
24 words
The polycrystalline silicon rod of claim 1 in which the starter filament contains less than 0.2 ppba boron and less than 0.2 ppba phosphorus.
Claim 11
Dependent Claim
33 words
The polycrystalline silicon rod of claim 2 in which the unicrystalline silicon from the float zoning exhibits a resistivity of at least 30,000 ohm-cm (donor) and a lifetime of at least 20,000 milliseconds.
References Cited (Backward Citations)
DE158655C
Cited
CA700233A
Cited
JPS5265719A
Cited
US4040848A
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JPS531463A
Cited
US4132763A
Cited
US4170667A
Cited
US4150168A
Cited
US4312700A
Cited
US4681652A
Cited
US4722764A
Cited
US4826668A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |