Patent US6171982B1 successfully refreshed from Google Patents.
US6171982B1
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Method and apparatus for heat-treating an SOI substrate and method of preparing an SOI substrate by using the same
Assignee: Canon Inc
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Filing: 1998-12-22
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Granted: 2001-01-09
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Expires: 2018-12-22
Abstract
Abstract An SOI substrate having on the surface thereof a single crystal silicon film formed on an insulator is heat-treated in a hydrogen-containing reducing atmosphere in order to smooth the surface and reduce the boron concentration without damaging the film thickness uniformity in a single wafer and among different wafers. The method is characterized in that the single crystal silicon film is arranged opposite to a member of non-oxidized silicon for heat treatment.
Inventors
- 👤 Nobuhiko Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:42
CPC Classifications
H; H10; H10D; H10D86/00; H10P; H10P95/00; H10P95/90; H10P95/906; H10P72/00; H10P72/04; H10P72/0431; H10P72/0436; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10P90/1916; H10P90/1922; H10P90/1924; H10W; H10W10/00; H10W10/10; H10W10/181
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
56 words
A method for heat-treating an SOI substrate having a silicon surface comprising a step of: heat-treating said SOI substrate in a hydrogen-containing reducing atmosphere, with keeping said SOI substrate in a state disposed opposite to a planar surface comprising a material comprised of a non-oxidized silicon as a main component with a predetermined distance separating them.
Claim 2
Independent Claim
56 words
A method for heat-treating an SOI substrate having a silicon surface comprising a step of: heat-treating said SOI substrate in a hydrogen-containing reducing atmosphere, with keeping said SOI substrate in a state disposed opposite to a planar surface comprising a material comprised of a non-oxidized silicon as a main component with a predetermined distance separating them.
Claim 3
Dependent Claim
32 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said material is selected from a group consisting of silicon, silicon carbide and silicon nitride.
Claim 4
Dependent Claim
24 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said silicon surface is an unpolished surface.
Claim 5
Dependent Claim
30 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said silicon surface has a surface roughness attributable to a porous silicon layer.
Claim 6
Dependent Claim
27 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said silicon surface has a surface roughness attributable to micro-cavities.
Claim 7
Dependent Claim
36 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said SOI substrate has a buried insulation film obtained as a result of oxygen ion implantation and heat treatment.
Claim 8
Dependent Claim
28 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said planar surface is obtained by removing a natural oxide film.
Claim 9
Dependent Claim
40 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein a plurality of said SOI substrates are arranged so as to have their respective said silicon surfaces arranged in parallel with each other.
Claim 10
Dependent Claim
43 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 8 , wherein each of said SOI substrates is arranged to face a rear surface of an adjacent SOI substrate from which rear surface any oxide film is removed.
Claim 11
Dependent Claim
31 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 8 , wherein any adjacent said SOI substrates are arranged with their silicon surfaces facing each other.
Claim 12
Dependent Claim
54 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein a plurality of SOI substrates are arranged coaxially at predetermined intervals and directed to a same direction; and a dummy substrate having said plane surface is arranged to face said silicon surface of the leading SOI substrate.
Claim 13
Dependent Claim
33 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said SOI substrate is placed in a container having an inner wall surface of non-oxidized silicon.
Claim 14
Dependent Claim
45 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said SOI substrate is placed in a container comprising an outer tube comprised of silicon oxide and an inner tube having an inner surface comprised of non-oxidized silicon.
Claim 15
Dependent Claim
45 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 13 , wherein hydrogen gas is supplied into said inner tube and exhausted from said inner tube by way of a flow path between the inner tube and the outer tube.
Claim 16
Dependent Claim
57 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein a plurality of said SOI substrates are supported by a support member having a surface comprising non-silicon oxide so as to be arranged in parallel with each other in a container having an inner wall surface also comprising non-oxidized silicon.
Claim 17
Dependent Claim
46 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein the root mean square of surface roughness in 1 μm square area of said silicon surface is made to be not greater than 0.4 nm after the heat treatment.
Claim 18
Dependent Claim
68 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein a plurality of said SOI substrates, each having a silicon surface, are arranged coaxially in parallel with each other at predetermined intervals to face a same direction and a dummy substrate having at least a non-oxidized silicon surface is arranged foremost to face the silicon surface of the leading SOI substrate.
Claim 19
Dependent Claim
28 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said SOI substrate has an Si layer formed by epitaxial growth.
Claim 20
Dependent Claim
33 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein the SOI layer of said SOI substrate has a thickness of not greater than 450 nm.
Claim 21
Dependent Claim
60 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein a flow rate of gas running near and in parallel with a principal surface of said SOI substrate is made smaller than a flow rate of gas running perpendicularly relative to a principal surface in an outer peripheral area of the SOI substrate.
Claim 22
Dependent Claim
37 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 20 , wherein the flow rate of gas running near the principal surface of said SOI substrate is made practically equal to 0.
Claim 23
Dependent Claim
40 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein a silicon oxide film of a rear surface of said SOI substrate is removed to expose the non-oxidized silicon of the rear surface.
Claim 24
Dependent Claim
59 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein a plurality of said SOI substrates are arranged such that each SOI substrate is placed on a tray having a rear surface of non-oxidized silicon with the SOI layer facing upward and vis-a-vis the rear surface of the tray located immediately thereabove.
Claim 25
Dependent Claim
42 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein a counter-surface constituting member containing silicon carbide as principal ingredient is arranged opposite to the SOI substrate with hydrogen gas interposed therebetween for heat treatment.
Claim 26
Dependent Claim
29 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein the hydrogen-containing reducing atmosphere substantially contains hydrogen or hydrogen and inert gases.
Claim 27
Dependent Claim
30 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said hydrogen-containing reducing atmosphere shows a dew point not higher than −92° C.
Claim 28
Dependent Claim
39 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said SOI substrate is supported by a member containing Si, SiC or SiN at least on its surface as the principal ingredient.
Claim 29
Dependent Claim
45 words
A method for heat-treating an SOI substrate having a silicon surface according to claim 1 , wherein said SOI substrate is so arranged in a container as to make its principal surface stand perpendicular relative to a main stream of gas introduced into the container.
Claim 30
Dependent Claim
29 words
A method of preparing an SOI substrate, which comprises the step of: smoothing a surface of the SOI substrate by a heat treatment method according to claim 1 .
Claim 31
Dependent Claim
34 words
A method of preparing an SOI substrate, which comprises the step of: reducing an impurity concentration of an SOI layer of the SOI substrate by a heat treatment method according to claim 1 .
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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) | 2004-01-09 | 2004-07-10 | 2005-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-01-09 | 2008-07-10 | 2009-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-01-09 | 2012-07-10 | 2013-01-09 | $7700.00 | Window Closed / Lapsed |