US5869387A
Expired / Lapsed
US
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Process for producing semiconductor substrate by heating to flatten an unpolished surface
Assignee: Canon Inc
•
Filing: 1995-03-13
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Granted: 1999-02-09
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Expires: 2015-03-13
Abstract
Abstract A process for producing a semiconductor substrate comprises heat-treating a substrate having a monocrystal thereon in a reducing atmosphere.
Inventors
- 👤 Nobuhiko Sato
- 👤 Takao Yonehara
- 👤 Kiyofumi Sakaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:55
CPC Classifications
C; C30; C30B; C30B29/00; C30B29/02; C30B29/06; C30B33/00; H; H10; H10F; H10F71/00; H10F71/139; H10P; H10P14/00; H10P14/20; H10P14/22; H10P14/24; H10P14/26; H10P14/265; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/2922; H10P14/2924; H10P14/2926; H10P14/32; H10P14/3202; H10P14/3204; H10P14/3211; H10P14/3242; H10P14/3256; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3451; H10P14/3452; H10P14/3458; H10P14/36; H10P14/38; H10P14/3802; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10P90/1922; H10P90/1924; H10P95/00; H10P95/06; H10P95/90; H10P95/906; H10W; H10W10/00; H10W10/10; H10W10/181; Y; Y02; Y02E; Y02E10/00; Y02E10/50
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
82 words
A process for producing a semiconductor substrate comprising: flattening an unpolished surface of a substrate, the surface comprising a monocrystalline semiconductor and having irregularities of several nm to several tens of nm in height and several nm to several hundreds of nm in cycle, the flattening comprising heat-treating the surface at a temperature lower than the melting point of the monocrystalline semiconductor in a reducing atmosphere comprising hydrogen to reduce the difference in height of the surface to 2 nm or less.
Claim 2
Dependent Claim
82 words
A process for producing a semiconductor substrate comprising: flattening an unpolished surface of a substrate, the surface comprising a monocrystalline semiconductor and having irregularities of several nm to several tens of nm in height and several nm to several hundreds of nm in cycle, the flattening comprising heat-treating the surface at a temperature lower than the melting point of the monocrystalline semiconductor in a reducing atmosphere comprising hydrogen to reduce the difference in height of the surface to 2 nm or less.
Claim 3
Dependent Claim
17 words
The process according to claim 1, wherein the atmosphere comprises a mixed gas of hydrogen and nitrogen.
Claim 4
Dependent Claim
19 words
The process according to claim 2, wherein the mixed gas consists of 90% of nitrogen and 10% of hydrogen.
Claim 5
Dependent Claim
21 words
The process according to claim 1, wherein the heat treatment is carried out at a pressure not higher than atmospheric pressure.
Claim 6
Dependent Claim
21 words
The process according to claim 4, wherein the heat treatment is carried out at a pressure not higher than 200 Torr.
Claim 7
Dependent Claim
21 words
The process according to claim 1, wherein the heat treatment is carried out at a temperature of 300° C. or higher.
Claim 8
Dependent Claim
21 words
The process according to claim 6, wherein the heat treatment is carried out at a temperature of 500° C. or higher.
Claim 9
Dependent Claim
21 words
The process according to claim 1, wherein the heat treatment is carried out at a temperature of 1200° C. or lower.
Claim 10
Dependent Claim
12 words
The process according to claim 1, wherein the monocrystalline semiconductor comprises silicon.
Claim 11
Dependent Claim
59 words
A process for producing a semiconductor substrate comprising: heat-treating a substrate having a monocrystalline semiconductor layer on an insulating layer on a support member or a light transmitting support member at a temperature lower than the melting point of the monocrystalline semiconductor layer in a reducing atmosphere comprising hydrogen to flatten an unpolished surface of the monocrystalline semiconductor layer.
Claim 12
Dependent Claim
59 words
A process for producing a semiconductor substrate comprising: heat-treating a substrate having a monocrystalline semiconductor layer on an insulating layer on a support member or a light transmitting support member at a temperature lower than the melting point of the monocrystalline semiconductor layer in a reducing atmosphere comprising hydrogen to flatten an unpolished surface of the monocrystalline semiconductor layer.
Claim 13
Dependent Claim
60 words
The process according to claim 10, wherein the surface of the monocrystalline semiconductor layer prior to to the heat treatment has irregularities of several nm to several tens of nm in height and several nm to several hundreds of nm in cycle, and wherein the heat treatment reduces the difference in height of the surface to 2 nm or less.
Claim 14
Dependent Claim
21 words
The process according to claim 10, wherein the heat treatment is carried out at a pressure not higher than atmospheric pressure.
Claim 15
Dependent Claim
21 words
The process according to claim 12, wherein the heat treatment is carried out at a pressure not higher than 200 Torr.
Claim 16
Dependent Claim
21 words
The process according to claim 10, wherein the heat treatment is carried out at a temperature of 300° C. or higher.
Claim 17
Dependent Claim
21 words
The process according to claim 14, wherein the heat treatment is carried out at a temperature of 500° C. or higher.
Claim 18
Dependent Claim
21 words
The process according to claim 10, wherein the heat treatment is carried out at a temperature of 1200° C. or lower.
Claim 19
Dependent Claim
13 words
The process according to claim 10, wherein the monocrystalline semiconductor layer comprises silicon.
Claim 20
Dependent Claim
83 words
A process for producing a semiconductor substrate comprising: flattening an unpolished surface of a substrate, the surface comprising a monocrystalline semiconductor and having irregularities of up to 30 nm, the flattening comprising heat-treating the surface at a temperature not lower than 500° C. and lower than the melting point of the monocrystalline semiconductor in a reducing atmosphere consisting essentially of (a) hydrogen, or (b) hydrogen and an inert gas, to reduce the difference in height of the surface to 2 nm or less.
Claim 21
Dependent Claim
83 words
A process for producing a semiconductor substrate comprising: flattening an unpolished surface of a substrate, the surface comprising a monocrystalline semiconductor and having irregularities of up to 30 nm, the flattening comprising heat-treating the surface at a temperature not lower than 500° C. and lower than the melting point of the monocrystalline semiconductor in a reducing atmosphere consisting essentially of (a) hydrogen, or (b) hydrogen and an inert gas, to reduce the difference in height of the surface to 2 nm or less.
Claim 22
Dependent Claim
18 words
The process according to claim 18, wherein the reducing atmosphere is a mixed gas of hydrogen and nitrogen.
Claim 23
Dependent Claim
16 words
The process according to claim 19, wherein the mixed gas is 90% nitrogen and 10% hydrogen.
Claim 24
Dependent Claim
21 words
The process according to claim 18, wherein the heat treatment is carried out at a pressure not higher than atmospheric pressure.
Claim 25
Dependent Claim
21 words
The process according to claim 21, wherein the heat treatment is carried out at a pressure not higher than 200 Torr.
Claim 26
Dependent Claim
21 words
The process according to claim 18, wherein the heat treatment is carried out at a temperature of 1200° C. or lower.
Claim 27
Dependent Claim
12 words
The process according to claim 18, wherein the monocrystalline semiconductor comprises silicon.
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