EP0592227A2
Expired / Lapsed
EP
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Fabrication of a thin film transistor and production of a liquid crystal display apparatus
Assignee: Sharp Corp
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Filing: 1993-10-07
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Granted: —
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Expires: 2013-10-07
Abstract
Abstract A thin film transistor includes: an insulating film having a surface; a semiconductor film formed on the surface of the insulating film; a source electrode and a drain electrode which are in contact with the semiconductor film; and a gate electrode which is electrically insulated from the semiconductor film. In the thin film transistor, a portion of the semiconductor film at distances of less than 500 angstroms from the surface of the insulating film contains at least silicon including a microcrystalline structure having a conductivity of 5 x 10⁻⁹ S/cm or more. Also, a method for fabricating such a thin film transistor is disclosed. The method includes a step of forming a semiconductor film including a silicon layer having a microcrystalline structure by repeatedly performing the following steps (1) and (2): (1) forming a silicon layer on an insulating film by decomposing a material gas including Si which is introduced into a reaction chamber of a plasma chemical vapor deposition apparatus; and (2) microcrystallizing the silicon layer by introducing the hydrogen gas into the chamber to perform a hydrogen plasma treatment for the silicon layer.
Inventors
- 👤 Yukihiko Nakata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 09:34
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/67; H10D30/6729; H10D30/673; H10D30/6732; C; C23; C23C; C23C16/00; C23C16/22; C23C16/24; C23C16/44; C23C16/50; C23C16/505; C23C16/509; C23C16/5096; C23C16/54; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0316; H10D30/0321; H10D30/674; H10D30/6741; H10D30/6743; H10D30/6745; H10D86/00; H10D86/01; H10D86/021; H10D86/0221; H10D86/0223; H10D86/40; H10D86/60; H10P; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2922; H10P14/32; H10P14/3202; H10P14/3238; H10P14/3241; H10P14/3242; H10P14/3244; H10P14/3251; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3438; H10P14/3441; H10P14/3444; H10P14/3451; H10P14/3452; H10P14/3454; H10P14/38; H10P14/3802; H10P95/00; H10P95/94
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
89 words
A thin film transistor comprising: an insulating film having a surface; an i-type semiconductor film formed on said surface of said insulating film; a source electrode and a drain electrode which are in contact with said semiconductor film; and a gate electrode which is electrically insulated from said semiconductor film, wherein a portion of said semiconductor film at distances of less than 500 angstroms from said surface of said insulating film contains at least silicon including a microcrystalline structure having a conductivity of 5 x 10⁻⁹ S/cm or more.
Claim 2
Dependent Claim
91 words
A thin film transistor comprising: an insulating film having a surface; a p-type or n-type semiconductor film formed on said surface of said insulating film; a source electrode and a drain electrode which are in contact with said semiconductor film; and a gate electrode which is electrically insulated from said semiconductor film, wherein a portion of said semiconductor film at distances of less than 500 angstroms from said surface of said insulating film contains at least silicon including a microcrystalline structure having a conductivity of 1 x 10⁻³ S/cm or more.
Claim 3
Dependent Claim
90 words
A thin film transistor comprising: an insulating film having a surface; a semiconductor film formed on said surface of said insulating film; a source electrode and a drain electrode which are in contact with said semiconductor film; and a gate electrode which is electrically insulated from said semiconductor film, wherein a portion of said semiconductor film at distances of less than 500 angstroms from said surface of said insulating film contains at least silicon including a microcrystalline structure having an amount of bound hydrogen of 10 atomic percent or less.
Claim 4
Dependent Claim
86 words
A thin film transistor comprising: an insulating film having a surface; a semiconductor film formed on said surface of said insulating film; a source electrode and a drain electrode which are in contact with said semiconductor film; and a gate electrode which is electrically insulated from said semiconductor film, wherein a portion of said semiconductor film at distances of less than 500 angstroms from said surface of said insulating film contains at least silicon including a microcrystalline structure having crystalline volume fraction of 10% or more.
Claim 5
Independent Claim
81 words
A method for fabricating a thin film transistor comprising a step of forming a semiconductor film including a silicon layer having a microcrystalline structure by repeatedly performing steps (1) and (2): (1) forming a silicon layer by decomposing a material gas including Si which is introduced into a reaction chamber of a plasma chemical vapor deposition apparatus; and (2) microcrystallizing said silicon layer by introducing said hydrogen gas into said chamber to perform a hydrogen plasma treatment for said silicon layer.
Claim 6
Dependent Claim
50 words
A method for fabricating a thin film transistor according to claim 5, further comprising a step of performing a hydrogen plasma treatment for an upper surface of an insulating film on which said semiconductor film is formed, prior to said step of forming said semiconductor film on said insulating film.
Claim 7
Dependent Claim
38 words
A method for fabricating a thin film transistor according to claim 5, wherein, in said step of forming said silicon layer, said silicon layer is formed to have a thickness in the range of 1 to 1000 angstroms.
Claim 8
Independent Claim
73 words
A method for fabricating a thin film transistor comprising: a first step for forming a silicon layer having a microcrystalline structure under a condition of a dilution ratio with hydrogen of 200 or more, said silicon layer having a thickness of 100 angstroms or less; and a second step for forming, on said silicon layer, another silicon layer having a microcrystalline structure under a condition of a dilution ratio with hydrogen of 2-100.
Claim 9
Independent Claim
103 words
A method for producing a liquid crystal display apparatus including thin film transistors, wherein a step of forming a semiconductor film for each of said thin film transistors comprises a step of forming a semiconductor film composed of a silicon layer having a microcrystalline structure by repeatedly performing steps (1) and (2): (1) forming an amorphous silicon layer on a substrate by decomposing a material gas including Si introduced into a reaction chamber of a plasma chemical vapor deposition apparatus by plasma; and (2) performing a hydrogen plasma treatment for said amorphous silicon layer by introducing a hydrogen gas into said reaction chamber.
Claim 10
Dependent Claim
109 words
A plasma chemical vapor deposition apparatus comprising: a reaction chamber for forming a thin semiconductor layer and for performing a hydrogen plasma treatment for said thin semiconductor layer; a first line, coupled with said reaction chamber, for introducing a hydrogen gas into said reaction chamber; a second line, coupled with said reaction chamber, for introducing a material gas used for forming said thin semiconductor layer into said reaction chamber; a third line, coupled with said second line, for exhausting said material gas from said second line; and switching means for switching between said second line for introducing said material gas and said third line for exhausting said material gas.
Claim 11
Dependent Claim
213 words
A plasma chemical vapor deposition apparatus comprising: a reaction chamber for forming a thin semiconductor layer and for performing a hydrogen plasma treatment for said thin semiconductor layer; a first line, coupled with said reaction chamber, for introducing a hydrogen gas into said reaction chamber; a second line, coupled with said reaction chamber, for introducing a material gas used for forming said thin semiconductor layer into said reaction chamber; a third line, coupled with said second line, for exhausting said material gas from said second line; a first valve provided on said second line between said reaction chamber and a coupling portion of said second line and said third line; a second valve provided on said third line; and control means for controlling the opening and closing said first valve and said second valve, wherein, when said thin semiconductor layer is formed, said control means controls said first valve to be open and said second valve to be closed, whereby said material gas is introduced into said reaction chamber, and when said hydrogen plasma treatment is performed for said thin semiconductor layer, said control means controls said second valve to be open and said first valve to be closed, whereby only the introduction of said material gas into said reaction chamber is stopped.
Claim 12
Independent Claim
79 words
A method for forming a thin semiconductor layer by plasma chemical vapour deposition comprising selectively supplying hydrogen gas and material gas including a semiconductor material into a reaction chamber, characterised by supplying the hydrogen gas continuously and the material gas intermittently whereby when hydrogen gas and material gas are simultaneously supplied a layer of said semiconductor material is deposited and when hydrogen gas only is supplied a hydrogen plasma treatment is performed on the deposited layer of semiconductor material.
References Cited (Backward Citations)
No citation records indexed.
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