US5529937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for fabricating thin film transistor
Assignee: Semiconductor Energy Laboratory Co Ltd
•
Filing: 1994-07-20
•
Granted: 1996-06-25
•
Expires: 2014-07-20
Abstract
Abstract After a pattern is transferred on silicon film crystallized by annealing, the silicon film is annealed by radiation of intense rays for a short time. Especially, in the crystallizing process by annealing, an element which promotes crystallization such as nickel is doped therein. The area not crystallized by annealing is also crystallized by radiation of intense rays and a condensed silicon film is formed. After a metal element which promotes crystallization is doped, annealing by light for a short time is performed by radiating intense rays onto the silicon film crystallized by annealing in an atmosphere containing halide. After the surface of the silicon film is oxidized by heating or by radiating intense rays in a halogenated atmosphere and an oxide film is formed on the silicon film, the oxide film is then etched. As a result, nickel in the silicon film is removed.
Inventors
- 👤 Hongyong Zhang
- 👤 Hideto Ohnuma
- 👤 Yasuhiko Takemura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:51
CPC Classifications
H; H10; H10P; H10P10/00; H10P36/00; H10P36/03; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0314; H10D30/0321; H10D86/00; H10D86/01; H10D86/021; H10D86/0221; H10D86/0223; H10D86/0225; H10P14/00; H10P14/20; H10P14/29; H10P14/2901; H10P14/2922; H10P14/32; H10P14/3202; H10P14/3238; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/38; H10P14/3802; H10P14/3806; H10P14/3808; H10P14/3816; H10P95/00; H10P95/40; H10P95/402; Y; Y10; Y10S; Y10S148/00; Y10S148/004; Y10S148/016; Y10S148/06
Claims Analysis
Total Claims: 64
Claim 1
Independent Claim
82 words
A method of fabricating a semiconductor device comprising: forming a non-monocrystal silicon film above a substrate; forming a catalyst element for promoting a crystallization of silicon in contact therewith; crystallizing the non-monocrystal silicon film by thermal annealing after forming said catalyst element wherein amorphous areas are left between crystals formed in the silicon film; and increasing the crystallinity of the thermally annealed non-monocrystal silicon film by irradiating said silicon film with light to crystallize said amorphous areas remaining after said crystallizing step.
Claim 2
Independent Claim
82 words
A method of fabricating a semiconductor device comprising: forming a non-monocrystal silicon film above a substrate; forming a catalyst element for promoting a crystallization of silicon in contact therewith; crystallizing the non-monocrystal silicon film by thermal annealing after forming said catalyst element wherein amorphous areas are left between crystals formed in the silicon film; and increasing the crystallinity of the thermally annealed non-monocrystal silicon film by irradiating said silicon film with light to crystallize said amorphous areas remaining after said crystallizing step.
Claim 3
Dependent Claim
36 words
The method of claim 1 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cr, Mn, Cu and Zn.
Claim 4
Dependent Claim
32 words
The method of claim 1 further comprising the step of forming an insulating film on said silicon film, and wherein said silicon film is irradiated by said light through said insulating film.
Claim 5
Dependent Claim
17 words
The method of claim 3 wherein the insulating film is made of silicon nitride or silicon oxide.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein the light has a wavelength of 4 μm to 0.5 μm.
Claim 7
Dependent Claim
18 words
The method of claim 5 wherein the radiating of the light is continued for 10 to 1000 seconds.
Claim 8
Dependent Claim
26 words
The method of claim 1 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Sc, Ti and V.
Claim 9
Dependent Claim
25 words
The method of claim 1 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Au and Ag.
Claim 10
Dependent Claim
20 words
The method of claim 1 wherein said silicon film is formed to a thickness of 300 Å to 1500 Å.
Claim 11
Dependent Claim
12 words
The method of claim 9 wherein said silicon film is 500 Å.
Claim 12
Independent Claim
107 words
A method of fabricating a semiconductor device comprising: forming a non-monocrystal silicon film above a substrate; disposing a catalyst element in contact with a selected region of said non-monocrystal silicon film; heating said so that crystallization of said silicon firm laterally proceeds from said selected region toward a region where said catalyst element is not disposed wherein amorphous areas are left between crystals formed in the silicon film; and promoting additional crystallization of the silicon film by radiating laser light or a light between near infrared radiation and visible radiation to the silicon film after said heating to crystallize said amorphous areas remaining after said crystallizing step.
Claim 13
Independent Claim
107 words
A method of fabricating a semiconductor device comprising: forming a non-monocrystal silicon film above a substrate; disposing a catalyst element in contact with a selected region of said non-monocrystal silicon film; heating said so that crystallization of said silicon firm laterally proceeds from said selected region toward a region where said catalyst element is not disposed wherein amorphous areas are left between crystals formed in the silicon film; and promoting additional crystallization of the silicon film by radiating laser light or a light between near infrared radiation and visible radiation to the silicon film after said heating to crystallize said amorphous areas remaining after said crystallizing step.
Claim 14
Dependent Claim
40 words
The method of claim 11 further comprising the step of neutralizing a dangling bond of silicon in the silicon film by thermally annealing the silicon film in an atmosphere containing hydrogen at a temperature of from 200° to 450° C.
Claim 15
Dependent Claim
26 words
The method of claim 11 wherein the light between the near infrared radiation and the visible radiation has a wavelength of 4 μm to 0.5 μm.
Claim 16
Dependent Claim
27 words
The method of claim 13 wherein the radiating of the light between the near infrared radiation and the visible radiation is continued for 10 to 1000 seconds.
Claim 17
Dependent Claim
36 words
The method of claim 11 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, It, Pt, Cr, Mn, Cu and Zn.
Claim 18
Dependent Claim
26 words
The method of claim 11 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Sc, Ti and V.
Claim 19
Dependent Claim
25 words
The method of claim 11 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Au and Ag.
Claim 20
Dependent Claim
20 words
The method of claim 11 wherein said silicon film is formed to a thickness of 300 Å to 1500 Å.
Claim 21
Dependent Claim
12 words
The method of claim 18 wherein said silicon film is 500 Å.
Claim 22
Independent Claim
106 words
A method of fabricating a semiconductor device comprising: forming a silicon film above a substrate; introducing a metal element which promotes crystallization of the silicon film into the amorphous silicon film; crystallizing the amorphous silicon film by thermal annealing wherein amorphous areas are left between crystals formed in the silicon film; and then reducing a density of the metal element in the silicon film by radiating a light onto the crystallized silicon film in an atmosphere containing chloride or fluoride gas, wherein crystallinity of said silicon film is further increased by the irradiation of said light to crystallize said amorphous areas remaining after said crystallizing step.
Claim 23
Independent Claim
106 words
A method of fabricating a semiconductor device comprising: forming a silicon film above a substrate; introducing a metal element which promotes crystallization of the silicon film into the amorphous silicon film; crystallizing the amorphous silicon film by thermal annealing wherein amorphous areas are left between crystals formed in the silicon film; and then reducing a density of the metal element in the silicon film by radiating a light onto the crystallized silicon film in an atmosphere containing chloride or fluoride gas, wherein crystallinity of said silicon film is further increased by the irradiation of said light to crystallize said amorphous areas remaining after said crystallizing step.
Claim 24
Dependent Claim
11 words
The method of claim 20 wherein the metal element is nickel.
Claim 25
Dependent Claim
40 words
The method of claim 20 further comprising the step of neutralizing a dangling bond of silicon in the silicon film by thermally annealing the silicon film in an atmosphere containing hydrogen at a temperature of from 200° to 450° C.
Claim 26
Dependent Claim
26 words
The method of claim 20 wherein in the reducing step, plasma excitation is generated in the atmosphere by means of a microwave or a high frequency.
Claim 27
Dependent Claim
19 words
The method of claim 20 wherein the light is emitted by one of a laser and a halogen lamp.
Claim 28
Dependent Claim
36 words
The method of claim 20 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cr, Mn, Cu and Zn.
Claim 29
Dependent Claim
26 words
The method of claim 20 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Sc, Ti and V.
Claim 30
Dependent Claim
25 words
The method of claim 20 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Au and Ag.
Claim 31
Dependent Claim
20 words
The method of claim 20 wherein said silicon film is formed to a thickness of 300 Å to 1500 Å.
Claim 32
Dependent Claim
12 words
The method of claim 28 wherein said silicon film is 500 Å.
Claim 33
Independent Claim
109 words
A method of fabricating a semiconductor device comprising: forming a non-monocrystal silicon film above a substrate; disposing a catalyst element in contact with a selected region of said non-monocrystal silicon film; heating said silicon film so that crystallization of said silicon film laterally proceeds from said selected region toward a region where said catalyst element is not disposed; selectively removing at least portions of said silicon film, said portions corresponding to said selected region where said element is disposed and to a region where said crystallization in a lateral direction terminates; and increasing a crystallinity of said silicon film by irradiating said silicon film with light after said removing.
Claim 34
Independent Claim
109 words
A method of fabricating a semiconductor device comprising: forming a non-monocrystal silicon film above a substrate; disposing a catalyst element in contact with a selected region of said non-monocrystal silicon film; heating said silicon film so that crystallization of said silicon film laterally proceeds from said selected region toward a region where said catalyst element is not disposed; selectively removing at least portions of said silicon film, said portions corresponding to said selected region where said element is disposed and to a region where said crystallization in a lateral direction terminates; and increasing a crystallinity of said silicon film by irradiating said silicon film with light after said removing.
Claim 35
Dependent Claim
19 words
The method of claim 30 wherein the light is emitted by one of a laser and a halogen lamp.
Claim 36
Dependent Claim
36 words
The method of claim 30 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cr, Mn, Cu and Zn.
Claim 37
Dependent Claim
26 words
The method of claim 30 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Sc, Ti and V.
Claim 38
Dependent Claim
25 words
The method of claim 30 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Au and Ag.
Claim 39
Dependent Claim
20 words
The method of claim 30 wherein said silicon film is formed to a thickness of 300 Å to 1500 Å.
Claim 40
Dependent Claim
12 words
The method of claim 35 wherein said silicon film is 500 Å.
Claim 41
Dependent Claim
56 words
The method of claim 30 further including the steps of introducing P or N type impurities into remaining portions of the silicon film after said selective removal of the portions of the silicon film corresponding to said selected regions where said element is disposed and to a region where said crystallization in a lateral direction terminates.
Claim 42
Dependent Claim
52 words
The method of claim 37 wherein P type impurity is introduced into a first portion remaining after said selective removal and N type impurity is introduced into a second portion remaining after said selective removal to provide at least a pair of semiconductor devices on a single substrate having different conductivity types.
Claim 43
Independent Claim
105 words
A method of fabricating a semiconductor device comprising: forming an amorphous silicon film on a substrate; introducing a metal element which promotes crystallization of the silicon film into the amorphous silicon film; crystallizing the amorphous silicon film by thermal annealing wherein amorphous areas are left between crystals formed in the silicon film; forming an oxide film on the surface of the crystallized silicon film in an oxidizing atmosphere containing chloride or fluoride gas; reducing the metal element by etching the oxide film; and increasing the crystallinity of said silicon film further by irradiation of light to crystallize said amorphous areas remaining after said crystallizing step.
Claim 44
Independent Claim
105 words
A method of fabricating a semiconductor device comprising: forming an amorphous silicon film on a substrate; introducing a metal element which promotes crystallization of the silicon film into the amorphous silicon film; crystallizing the amorphous silicon film by thermal annealing wherein amorphous areas are left between crystals formed in the silicon film; forming an oxide film on the surface of the crystallized silicon film in an oxidizing atmosphere containing chloride or fluoride gas; reducing the metal element by etching the oxide film; and increasing the crystallinity of said silicon film further by irradiation of light to crystallize said amorphous areas remaining after said crystallizing step.
Claim 45
Dependent Claim
34 words
The method of claim 39 wherein the formation of the oxide film is performed by plasma excitation caused by a microwave or a high frequency in the oxidizing atmosphere containing chloride or fluoride gas.
Claim 46
Dependent Claim
39 words
The method of claim 39 wherein the formation of the oxide film is performed by radiating one of a laser light and a halogen lamp light to the silicon film in the oxidizing atmosphere containing chloride or fluoride gas.
Claim 47
Dependent Claim
36 words
The method of claim 39 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cr, Mn, Cu and Zn.
Claim 48
Dependent Claim
26 words
The method of claim 39 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Sc, Ti and V.
Claim 49
Dependent Claim
25 words
The method of claim 39 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Au and Ag.
Claim 50
Dependent Claim
20 words
The method of claim 39 wherein said silicon film is formed to a thickness of 300 Å to 1500 Å.
Claim 51
Dependent Claim
12 words
The method of claim 45 wherein said silicon film is 500 Å.
Claim 52
Independent Claim
120 words
A method of fabricating a semiconductor device comprising: forming a silicon film above a glass substrate; disposing a catalyst element in contact with at least a portion of said silicon film, said catalyst element being capable of promoting a crystallization of silicon; crystallizing said silicon film by thermal annealing at a temperature which is not higher than a distortion point of said glass substrate wherein amorphous areas are left between crystals formed in the silicon film; irradiating said silicon film with light after said thermal annealing in order to further increase the crystallinity of said silicon film to crystallize said amorphous areas remaining after said crystallizing step, wherein said silicon film is exposed to an oxidizing atmosphere during said irradiating.
Claim 53
Independent Claim
120 words
A method of fabricating a semiconductor device comprising: forming a silicon film above a glass substrate; disposing a catalyst element in contact with at least a portion of said silicon film, said catalyst element being capable of promoting a crystallization of silicon; crystallizing said silicon film by thermal annealing at a temperature which is not higher than a distortion point of said glass substrate wherein amorphous areas are left between crystals formed in the silicon film; irradiating said silicon film with light after said thermal annealing in order to further increase the crystallinity of said silicon film to crystallize said amorphous areas remaining after said crystallizing step, wherein said silicon film is exposed to an oxidizing atmosphere during said irradiating.
Claim 54
Dependent Claim
36 words
The method of claim 47 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cr, Mn, Cu and Zn.
Claim 55
Dependent Claim
26 words
The method of claim 47 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Sc, Ti and V.
Claim 56
Dependent Claim
25 words
The method of claim 47 wherein the catalyst element which promotes the crystallization comprises a metal selected from the group consisting of Au and Ag.
Claim 57
Dependent Claim
20 words
The method of claim 47 wherein said silicon film is formed to a thickness of 300 Å to 1500 Å.
Claim 58
Dependent Claim
12 words
The method of claim 51 wherein said silicon film is 500 Å.
Claim 59
Independent Claim
111 words
A method of fabricating a semiconductor device comprising: forming a non-monocrystal silicon film above a substrate; forming a nickel film for promoting a crystallization of silicon in contact therewith; annealing said silicon film to form a nickel silicide layer in at least a portion of the silicon film in contact with the nickel film; etching said nickel film; crystallizing the non-monocrystal silicon film by thermal annealing after etching said nickel film wherein amorphous areas are left between crystals formed in the silicon film, and increasing the crystallinity of the thermally annealed non-monocrystal silicon film by irradiating said silicon film with light to crystallize said amorphous areas remaining after said crystallizing step.
Claim 60
Independent Claim
111 words
A method of fabricating a semiconductor device comprising: forming a non-monocrystal silicon film above a substrate; forming a nickel film for promoting a crystallization of silicon in contact therewith; annealing said silicon film to form a nickel silicide layer in at least a portion of the silicon film in contact with the nickel film; etching said nickel film; crystallizing the non-monocrystal silicon film by thermal annealing after etching said nickel film wherein amorphous areas are left between crystals formed in the silicon film, and increasing the crystallinity of the thermally annealed non-monocrystal silicon film by irradiating said silicon film with light to crystallize said amorphous areas remaining after said crystallizing step.
Claim 61
Dependent Claim
25 words
The method of claim 53 wherein said annealing step to form nickel silicide is performed at a temperature of approximately 450° C. for one hour.
Claim 62
Dependent Claim
21 words
The method of claim 54 wherein said crystallizing step is performed at a temperature of approximately 550° C. for eight hours.
Claim 63
Independent Claim
98 words
A method of fabricating a semiconductor device comprising: forming a non-monocrystal silicon film on a substrate; crystallizing the non-monocrystal silicon film by thermal annealing; then, radiating a light to the crystallized silicon film, wherein the crystallized silicon film is maintained at a temperature of 200° to 500° C. in a first period, at a temperature of 800° to 1300° C. in a second period subsequent to the first period, and a temperature of 200° to 500° C. in a third period subsequent to the second period, wherein said first, second and third periods occur during said radiating step.
Claim 64
Independent Claim
98 words
A method of fabricating a semiconductor device comprising: forming a non-monocrystal silicon film on a substrate; crystallizing the non-monocrystal silicon film by thermal annealing; then, radiating a light to the crystallized silicon film, wherein the crystallized silicon film is maintained at a temperature of 200° to 500° C. in a first period, at a temperature of 800° to 1300° C. in a second period subsequent to the first period, and a temperature of 200° to 500° C. in a third period subsequent to the second period, wherein said first, second and third periods occur during said radiating step.
References Cited (Backward Citations)
USRE28385E
Cited
USRE28386E
Cited
US4226898A
Cited
US4231809A
Cited
US4331709A
Cited
US4300989A
Cited
US4379020A
Cited
US5262350A
Cited
US5296405A
Cited
US5221423A
Cited
US5225355A
Cited
US5043224A
Cited
JPH02140915A
Cited
US5200630A
Cited
US5278093A
Cited
US5313075A
Cited
US5147826A
Cited
US5262654A
Cited
US5308998A
Cited
US5254480A
Cited
US5298075A
Cited
US5403772A
Cited
US5275851A
Cited
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