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Method for forming a film and method for manufacturing a thin film transistor

Assignee: Fujitsu Ltd
•
Filing: 1993-02-09
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Granted: 1996-01-02
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Expires: 2013-02-09
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Abstract

Abstract A crystal silicon film deposited on an insulating film made of a binary system material or a binary system semiconductor film formed by an atomic layer deposition method has a grain as large as approximately 200 nm. Thus, the mobility of carriers is increased. The crystal silicon thereof is grown within a temperature range of 250° C. to 400° C. Accordingly, when a planar type thin film transistor, an inverted stagger type thin film transistor or a stagger type thin film transistor is formed using crystal silicon formed on these films made of a binary system material, transistor characteristics thereof are improved. Further, when an impurity containing silicon film is formed by a chemical vapor deposition method between a source electrode and a drain electrode of a thin film transistor and a silicon film connected to these electrodes, and a flow rate of impurity containing gas is regulated so that impurity density becomes larger as approaching to the source electrode and the drain electrode, a leakage current in an OFF-state of the transistor is reduced. Since the impurity containing silicon film is grown by a chemical vapor deposition method in this case, the impurity density thereof can be controlled easily and the control accuracy is also improved.

Inventors

  • 👤 Tomotaka Matsumoto
  • 👤 Jun Inoue
  • 👤 Teruhiko Ichimura
  • 👤 Yuji Murata
  • 👤 Junichi Watanabe
  • 👤 Yoshio Nagahiro
  • 👤 Mari Hodate
  • 👤 Kenichi Oki
  • 👤 Masahiro Okabe

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 01:14
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/455; C23C16/45523; C23C16/45525; C23C16/22; C23C16/30; C23C16/40; C23C16/403; H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0314; H10D30/0316; H10D30/0321; H10D30/60; H10D30/601; H10D30/67; H10D30/6704; H10D30/6713; H10D30/6715; H10D30/6729; H10D30/673; H10D30/6731; H10D30/6732; H10D30/674; H10D30/6741; H10D30/6743; H10D30/6745; H10D86/00; H10D86/01; H10D86/03; H10P; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2922; H10P14/32; H10P14/3202; H10P14/3238; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; Y; Y10; Y10S; Y10S148/00; Y10S148/15; Y10S148/169

Claims Analysis

Total Claims: 27
Claim 1
Independent Claim 131 words
A method for forming a film comprising the steps of: a) depositing a film formed of a binary system material on a base substance by an atomic layer deposition method in which the base substance on which the film is formed is exposed separately to two or more ambiences, one of which contains a first atom of the binary system material and the other of which contains a second atom of the binary system material; and b) growing poly-crystalline silicon on the film formed of the binary system material, the binary system material film is Al 2 O 3 , and crystal orientation of the top face of the film orients to a face (012), and crystal orientation of the top face of the poly-crystalline silicon orients to a face (100).
Claim 2
Independent Claim 131 words
A method for forming a film comprising the steps of: a) depositing a film formed of a binary system material on a base substance by an atomic layer deposition method in which the base substance on which the film is formed is exposed separately to two or more ambiences, one of which contains a first atom of the binary system material and the other of which contains a second atom of the binary system material; and b) growing poly-crystalline silicon on the film formed of the binary system material, the binary system material film is Al 2 O 3 , and crystal orientation of the top face of the film orients to a face (012), and crystal orientation of the top face of the poly-crystalline silicon orients to a face (100).
Claim 3
Dependent Claim 57 words
A method for forming a film according to claim 1, further comprising the step of: c) moving the base substance between said step a) of depositing the film formed of the binary system material and said step b) of growing poly-crystalline silicon, said steps a)-c) being performed in atmosphere having a pressure less than one atmospheric pressure.
Claim 4
Dependent Claim 36 words
A method for forming a film according to claim 1, wherein in said step a) the film formed of the binary system material is a film composed of a group III and a group V element.
Claim 5
Dependent Claim 30 words
A method for forming a film according to claim 1, wherein the binary system material film is any one of a GaP film, an AlP film and a ZnS film.
Claim 6
Dependent Claim 36 words
A method for forming a film according to claim 1, wherein in said step a) the film formed of the binary system material is formed at a substrate temperature less than or equal to 400° C.
Claim 7
Dependent Claim 29 words
A method for forming a film according to claim 1, wherein one of the ambiences is kept at a temperature which is different from a temperature of other ambiences.
Claim 8
Dependent Claim 45 words
A method for forming a film according to claim 1, wherein in said step a) the film formed of the binary system material is an Al 2 O 3 film formed by exposing the base substance to gas containing oxygen and gas containing aluminum alternately.
Claim 9
Dependent Claim 72 words
A method for forming a film according to claim 7, wherein the Al 2 O 3 film is exposed to Al containing gas to grow an Al layer on its top surface, and then the base substance is conveyed to an area where the poly-crystalline silicon grows while exposing the Al layer to another Al containing gas having a temperature which is kept below a temperature at which aluminum does not grow.
Claim 10
Dependent Claim 21 words
A method for forming a film according to claim 8, wherein the gas containing aluminum is Al(CH 3 ) 3 .
Claim 11
Dependent Claim 33 words
A method for forming a film according to claim 1, wherein in said step b) the poly-crystalline silicon film is formed in an ambience at a temperature of 250° C. to 400° C.
Claim 12
Dependent Claim 37 words
A method for forming a film according to claim 1, wherein in said step b) the growth of the poly-crystalline silicon film is by a plasma chemical vapor deposition method using reaction gas containing hydrogen and silane.
Claim 13
Dependent Claim 56 words
A method for forming a film according to claim 1, further comprising the substep of: growing a silicon containing insulating film which becomes the foundation of the film formed of the binary system material on the base substance before said step a) of depositing the film formed of the binary system material on the base substance.
Claim 14
Dependent Claim 30 words
A method for forming a film according to claim 12, wherein the silicon containing insulating film is one of a SiN film, a SiON film and a SiO 2 film.
Claim 15
Independent Claim 164 words
A method for manufacturing a thin film transistor comprising the steps of: a) depositing a film formed of a binary system material by an atomic layer deposition method in which an object substance on which a film is formed is exposed sequentially to two or more ambiences containing two atoms individually forming a binary system material; b) growing a poly-crystalline silicon film on the film formed of the binary system material, the binary system material film is Al 2 O 3 , crystal orientation of the top face of the film orient to a face (012) and crystal orientation of the top face of the polycrystalline silicon orient to a face (100); c) forming a gate insulator on the polycrystalline silicon film; d) forming a gate electrode on the gate insulator; and e) forming a source layer in the poly-crystalline silicon film on one side of the gate electrode and forming a drain layer in the poly-crystalline silicon film on the other side thereof.
Claim 16
Independent Claim 164 words
A method for manufacturing a thin film transistor comprising the steps of: a) depositing a film formed of a binary system material by an atomic layer deposition method in which an object substance on which a film is formed is exposed sequentially to two or more ambiences containing two atoms individually forming a binary system material; b) growing a poly-crystalline silicon film on the film formed of the binary system material, the binary system material film is Al 2 O 3 , crystal orientation of the top face of the film orient to a face (012) and crystal orientation of the top face of the polycrystalline silicon orient to a face (100); c) forming a gate insulator on the polycrystalline silicon film; d) forming a gate electrode on the gate insulator; and e) forming a source layer in the poly-crystalline silicon film on one side of the gate electrode and forming a drain layer in the poly-crystalline silicon film on the other side thereof.
Claim 17
Dependent Claim 37 words
A method for manufacturing a thin film transistor according to claim 14, wherein the binary system material film formed in said step a) is any one of a GaP film, an AlP film and a ZnS film.
Claim 18
Dependent Claim 36 words
A method for manufacturing a thin film transistor according to claim 14, wherein the binary system material film formed in said step a) is formed at a substrate temperature less than or equal to 400° C.
Claim 19
Dependent Claim 40 words
A method for manufacturing a thin film transistor according to claim 14, further comprising, before said step a), the step of growing a silicon containing insulating film which becomes the foundation of the film formed of the binary system material.
Claim 20
Dependent Claim 32 words
A method for manufacturing a thin film transistor according to claim 17, wherein the silicon containing insulating film is one of a SiN film, a SiON film and a SiO 2 film.
Claim 21
Dependent Claim 33 words
A method for manufacturing a thin film transistor according to claim 14, wherein the poly-crystalline silicon film formed in said step b) is grown at a temperature between 250° C. and 400° C.
Claim 22
Independent Claim 161 words
A method for manufacturing a thin film transistor comprising the steps of: a) forming a gate electrode; b) depositing a film formed of a binary system material on the gate electrode by an atomic layer deposition method in which a base substance on which a film is formed is exposed consecutively to each of two or more ambiences containing two atoms individually forming the binary system material; c) growing a poly-crystalline silicon film on the film formed of the binary system material, the binary system material is Al 2 O 3 , and crystal orientation of the top face of the film orients to a face (012) and crystal orientation of the top face of the poly-crystalline silicon orients to a face (100); d) forming a contact film composed of an impurity containing silicon on the crystal silicon film; and e) forming a source electrode and a drain electrode isolated from each other in the upper part of the gate electrode.
Claim 23
Independent Claim 161 words
A method for manufacturing a thin film transistor comprising the steps of: a) forming a gate electrode; b) depositing a film formed of a binary system material on the gate electrode by an atomic layer deposition method in which a base substance on which a film is formed is exposed consecutively to each of two or more ambiences containing two atoms individually forming the binary system material; c) growing a poly-crystalline silicon film on the film formed of the binary system material, the binary system material is Al 2 O 3 , and crystal orientation of the top face of the film orients to a face (012) and crystal orientation of the top face of the poly-crystalline silicon orients to a face (100); d) forming a contact film composed of an impurity containing silicon on the crystal silicon film; and e) forming a source electrode and a drain electrode isolated from each other in the upper part of the gate electrode.
Claim 24
Dependent Claim 40 words
A method for manufacturing a thin film transistor according to claim 20, wherein in said step b) the film formed of a binary system material is formed in an ambience at a temperature less than or equal to 400° C.
Claim 25
Dependent Claim 43 words
A method for manufacturing a thin film transistor according to claim 20, comprising, before said step a), a step of growing a silicon containing insulating film covering the gate electrode and becoming the foundation of the film formed of a binary system material.
Claim 26
Dependent Claim 31 words
A method for manufacturing a thin film transistor according to claim 22, wherein the silicon containing film is one of a SiN film, a SiON film and a SiO 2 film.
Claim 27
Dependent Claim 31 words
A method for manufacturing a thin film transistor according to claim 20, wherein, in said step c), the poly-crystalline silicon film grows at a temperature of 250° C. to 400° C.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-01-01 1999-07-03 2000-01-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-01-01 2003-07-03 2004-01-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-01-01 2007-07-03 2008-01-02 $7700.00 Window Closed / Lapsed

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