EP0069580A2
Expired / Lapsed
EP
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Method of producing thin films of silicon
Assignee: Tonen General Sekiyu KK
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Filing: 1982-07-05
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Granted: —
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Expires: 2002-07-05
Abstract
Abstract A method of producing thin films of silicon involves placing a p-type or n-type thin film (15) of silicon in a plasma atmosphere in a chamber (9) to which at least one element selected from the gases fluorine, chlorine, bromine, iodine and hydrogen are fed from sources (4 - 7) thereof, whereby the concentration of an impurity element or dopant in the surface of the film is decreased and accordingly is replaced by the plasma element(s) to a predetermined depth. Subsequent deposition of specified silicon layers can be accomplished without fear of their characters being altered by migration of said dopant from the film into the superposed layers.
Inventors
- 👤 Kazunobu Tanaka
- 👤 Akihisa Matsuda
- 👤 Toshihiko Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 12:08
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10D; H10D62/00; H10D62/40; H10D62/80; H10D62/83; H10D62/834; H10P14/24; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3438; H10P14/3441; H10P14/3442; H10P95/00; H10P95/94
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
69 words
A method of preparing thin films of silicon, characterized in that a p-type or n-type thin film of silicon is placed in a plasma atmosphere of at least one element selected from fluorine, chlorine, bromine, iodine, and hydrogen, the concentration of an impurity element is decreased and accordingly said impurity element is replaced by said plasma element(s) in a surface portion of said silicon film of a predetermined depth.
Claim 2
Independent Claim
69 words
A method of preparing thin films of silicon, characterized in that a p-type or n-type thin film of silicon is placed in a plasma atmosphere of at least one element selected from fluorine, chlorine, bromine, iodine, and hydrogen, the concentration of an impurity element is decreased and accordingly said impurity element is replaced by said plasma element(s) in a surface portion of said silicon film of a predetermined depth.
Claim 3
Dependent Claim
39 words
A method according to claim 1, characterized in that the pressure during plasma discharge of said at least one element is controlled so as to maintain flow in the vessel holding said plasma atmosphere in a viscous flow region.
Claim 4
Dependent Claim
39 words
A method according to claim 2, characterized in that said pressure during plasma discharge of fluorine, chlorine, bromine, iodine, or hydrogen gas is in the range from 1.5 x 10 2 to 3 torrs (0.02 to 4 m bars).
Claim 5
Dependent Claim
38 words
A method according to claim 1, 2 or 3, characterized in that the said depth in which the impurity concentration decreases is controlled by varying the electric power density within a range from 0.5 to 50 W/ cm2.
Claim 6
Dependent Claim
28 words
A method according to claim 4, characterized in that the said impurity concentration is decreased from o the surface down to a depth of 5000 A (500 nm).
Claim 7
Independent Claim
28 words
A method according to any of claims 1 to 5, characterized in that the thin film is a single-crystal silicon semiconductor of silicon or an amorphous silicon semiconductor.
Claim 8
Independent Claim
34 words
A method according to any of claims 1 to 5, characterized. in that the thin film of silicon is a silicon semiconductor of an amorphous layer in which microcrystalline particles are mixed and dispersed.
Claim 9
Dependent Claim
46 words
A method according to claim 1 or any of claims 2 to 7, characterized in that after reducing the concentration of said impurity element and accordingly replacing it by said plasma element(s), an n-type or p-type thin film of silicon is deposited on said thin film.
Claim 10
Dependent Claim
56 words
A method according to claim 1 or any of claims 2 to 7, characterized in that after reducing the concentration of said impurity element and accordingly replacing it by said plasma element(s) an i-type thin film of silicon and further an n-type or p-type thin film of the same material are deposited on said plasma-treated film.
Claim 11
Dependent Claim
105 words
A method according to claim 1 or any of claims 2 to 7, characterized in.that a thin film substrate of silicon doped with an impurity element is subjected to said plasma treatment in a.plasma atmosphere of a gaseous mixture consisting of at least one element selected from fluorine, chlorine, and hydrogen, and a gas containing a second impurity element dissimilar to the originally added impurity in said silicon film substrate, whereby the concentration of said original impurity is decreased in a surface portion of a predetermined depth while, concurrently, the substrate is doped to a desired depth with the second impurity contained in the plasma.
Claim 12
Dependent Claim
37 words
A method according to claim 10, characterized in that the pressure during plasma discharge of said gaseous mixture is controlled so as to maintain flow in the vessel holding the plasma atmosphere in a viscous flow region.
Claim 13
Dependent Claim
33 words
A method according to claim 10 or claim 11, characterized in that said pressure during plasma discharg in the range from 1.5 x 10 -2 to 3 torrs (0.02 to 4 m bars)
Claim 14
Dependent Claim
77 words
A method according to claim 10, 11 or 12, characterized in that said depth of substrate in which the concentration of said original impurity is decreased and said depth of doping with the new impurity are controlled by changing the ratio of the second impurity element gas to the said selected element gas within a range from 10 -5 to 10 -1 and power density is controlled within a range from 0.5 to 50 W/cm 2 .
Claim 15
Dependent Claim
43 words
A method according to claim 10, 11, 12 or 13, characterized in that the film substrate is a single-crystal semiconductor of silicon, or an amorphous silicon semiconductor, or a silicon semiconductor of an amorphous layer in which microcrystalline particles are mixed and dispersed.
References Cited (Backward Citations)
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