Patent US4549926A successfully refreshed from Google Patents.
US4549926A
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US
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Method for growing monocrystalline silicon on a mask layer
Assignee: Fairchild Semiconductor Corp
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Filing: 1983-11-18
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Granted: 1985-10-29
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Expires: 2003-11-18
Abstract
Abstract A monocrystalline silicon layer is formed on a mask layer on a semiconductor substrate. An apertured mask layer is disposed on the substrate, and an epitaxial layer is then grown by a two-step deposition/etching cycle. By repeating the deposition/etching cycle a predetermined number of times, monocrystalline silicon will be grown from the substrate surface, through the mask aperture, and over the mask layer.
Inventors
- 👤 John F. Corboy, Jr.
- 👤 Lubomir L. Jastrzebski
- 👤 Scott C. Blackstone
- 👤 Robert H. Pagliaro, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:10
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/24; H10P14/27; H10P14/271; H10P14/276; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; Y; Y10; Y10S; Y10S438/00; Y10S438/969
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
192 words
A method for forming monocrystalline silicon over a mask layer comprising: providing a semiconductor substrate having a monocrystalline portion at a surface thereof and having a mask layer on said surface, the mask layer having an aperture to said monocrystalline portion; depositing silicon from a silicon-source gas for a period substantially equal to a critical time, so as to form monocrystalline silicon on exposed monocrystalline silicon regions and non-monocrystalline silicon on the mask layer, said critical time being a time at which said non-monocrystalline silicon can be removed from the mask layer by etching in situ while retaining a portion of the deposited monocrystalline silicon; etching in a silicon-etching as, in situ, directly after said depositing, so as to remove the non-monocrystalline silicon from the mask layer while retaining a portion of the deposited monocrystalline silicon; repeating said deposition and etching cycle, so as to achieve a monocrystalline silicon island extending from the substrate surface at the mask aperture and overlapping the mask layer a predetermined distance; and removing the silicon overlying each mask aperture so as to expose the substrate surface and form a cavity between portions of deposited monocrystalline silicon.
Claim 2
Independent Claim
192 words
A method for forming monocrystalline silicon over a mask layer comprising: providing a semiconductor substrate having a monocrystalline portion at a surface thereof and having a mask layer on said surface, the mask layer having an aperture to said monocrystalline portion; depositing silicon from a silicon-source gas for a period substantially equal to a critical time, so as to form monocrystalline silicon on exposed monocrystalline silicon regions and non-monocrystalline silicon on the mask layer, said critical time being a time at which said non-monocrystalline silicon can be removed from the mask layer by etching in situ while retaining a portion of the deposited monocrystalline silicon; etching in a silicon-etching as, in situ, directly after said depositing, so as to remove the non-monocrystalline silicon from the mask layer while retaining a portion of the deposited monocrystalline silicon; repeating said deposition and etching cycle, so as to achieve a monocrystalline silicon island extending from the substrate surface at the mask aperture and overlapping the mask layer a predetermined distance; and removing the silicon overlying each mask aperture so as to expose the substrate surface and form a cavity between portions of deposited monocrystalline silicon.
Claim 3
Dependent Claim
20 words
A method in accordance with claim 1, further comprising: including a silicon-etching gas with the silicon-source gas during said depositing.
Claim 4
Dependent Claim
13 words
A method in accordance with claim 1, wherein the substrate is monocrystalline material.
Claim 5
Dependent Claim
36 words
A method in accordance with claim 1, wherein the substrate is polycrystalline material having a grain size greater than the mask aperture size and further comprising: locating the mask aperture within the boundaries of a grain.
Claim 6
Dependent Claim
28 words
A method in accordance with claim 1, further comprising: the mask layer including a plurality of apertures, each aperture being located over a monocrystalline portion of the substrate.
Claim 7
Dependent Claim
34 words
A method in accordance with claim 1, wherein: the mask layer comprises a material selected from the group consisting of SiO 2 , Si 3 N 4 , and Al 2 O 3 .
Claim 8
Dependent Claim
33 words
A method in accordance with claim 1, wherein: the silicon-source gas is selected from the group consisting of SiCl 4 , SiH 2 Cl 2 , SiHCl 3 , and SiH 4 .
Claim 9
Dependent Claim
35 words
A method in accordance with claim 1, wherein: said depositing silicon is from a gas mixture which comprises approximately 0.6 volume percent silicon-source gas, 0.6 volume percent HCl, and 98.8 volume percent H 2 .
Claim 10
Dependent Claim
30 words
A method in accordance with claim 1, wherein: the etching is performed in a gas mixture which comprises approximately 1.2 volume percent HCl and 98.8 volume percent H 2 .
Claim 11
Dependent Claim
8 words
A method in accordance with claim 1, comprising:
Claim 12
Dependent Claim
15 words
depositing and etching within a reactor wherein the temperature range is approximately 1050° C.-1200° C.
Claim 13
Dependent Claim
15 words
depositing and etching within a reactor wherein the temperature range is approximately 1050° C.-1200° C.
Claim 14
Dependent Claim
31 words
A method in accordance with claim 1, wherein the deposition and etching cycle comprises: depositing for approximately 30 seconds to 4 minutes; and etching for approximately 20 seconds to 2 minutes.
Claim 15
Dependent Claim
13 words
A method in accordance with claim 1, wherein the silicon-etching gas comprises HCl.
Claim 16
Dependent Claim
18 words
A method in accordance with claim 1, wherein said depositing further includes a carrier gas which comprises hydrogen.
Claim 17
Dependent Claim
29 words
A method in accordance with claim 1, comprising: repeating the deposition and etching cycle so as to form a layer of monocrystalline silicon over substantially the entire mask layer.
Claim 18
Dependent Claim
18 words
A method in accordance with claim 1 further comprising: filling each of said cavities with a preselected material.
Claim 19
Dependent Claim
64 words
A method in accordance with claim 1, further comprising: forming a second apertured mask layer, the second mask layer being located on the surface of the deposited monocrystalline silicon; and repeating the deposition and etching cycle of claim 1 so as to achieve at each aperture in the second mask layer a monocrystalline silicon island extending from the surface of the deposited monocrystalline silicon.
Claim 20
Dependent Claim
15 words
A method in accordance with claim 15, wherein said preselected material comprises a dielectric material.
Claim 21
Dependent Claim
15 words
A method in accordance with claim 15, wherein said preselected material comprises a resistive material.
Claim 22
Dependent Claim
15 words
A method in accordance with claim 15, wherein said preselected material comprises a conducting material.
Claim 23
Dependent Claim
29 words
A method in accordance with claim 5, comprising: repeating the deposition and etching cycle so as to form a layer of monocrystalline silicon over substantially the entire mask layer.
Claim 24
Dependent Claim
18 words
A method in accordance with claim 5, further comprising: filling each of said cavities with a preselected material.
Claim 25
Dependent Claim
63 words
A method in accordance with claim 5, further comprising: forming a second apertured mask layer, the second mask layer being located on the surface of the deposited monocrystalline silicon; and repeating the deposition and etching cycle of claim 1 so as to achieve at each aperture in the second mask layer a monocrystalline island extending from the surface of the deposited monocrystalline silicon.
Claim 26
Dependent Claim
27 words
A method in accordance with claim 22, further comprising: repeating the deposition and etching cycle until said monocrystalline silicon island overlaps the mask layer a predetermined distance.
Claim 27
Dependent Claim
27 words
A method in accordance with claim 17, further comprising: repeating the deposition and etching cycle until said monocrystalline silicon island overlaps the mask layer a predetermined distance.
References Cited (Backward Citations)
US3239372A
Cited
GB963799A
Cited
US3425879A
Cited
US3746908A
Cited
GB1358438A
Cited
US3985590A
Cited
US3945864A
Cited
US4141765A
Cited
USPTO Annuity & Maintenance Windows
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| 3.5 Years (Year 4) | 1988-10-28 | 1989-04-29 | 1989-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-28 | 1993-04-29 | 1993-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-28 | 1997-04-29 | 1997-10-29 | $7700.00 | Window Closed / Lapsed |