EP0474474A2
Expired / Lapsed
EP
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Semiconductor light valve device and process for fabricating the same
Assignee: Seiko Instruments Inc
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Filing: 1991-09-04
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Granted: —
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Expires: 2011-09-04
Abstract
Abstract The invention provides a semi-conductor light valve device and a process for fabricating the same. The device comprises an insulating substrate (7) having a semi-conductor single crystal thin film (1) over at least a portion thereof and providing a pixel array region and a peripheral circuit region. The pixel array region includes a plurality of switch elements (2) for selectively energising a plurality of pixel electrodes (3), and the peripheral circuit region includes drive circuits (15, 16) for operating the switch elements. At least circuit elements of the drive circuits are formed from the semi-conductor single crystal thin film. In the fabricating process, the semi-conductor single crystal thin film and the insulating substrate are formed as a composite substrate by adhering a semiconductor single crystal plate to the surface of the insulating substrate and by polishing the single crystal plate. The circuit elements of the drive circuits are then formed by treating the single crystal plate. <IMAGE>
Inventors
- 👤 Hiroaki Takasu
- 👤 Yoshikazu Kojima
- 👤 Masaaki Kamiya
- 👤 Tsuneo Yamazaki
- 👤 Hiroshi Suzuki
- 👤 Masaaki Taguchi
- 👤 Ryuichi Takano
- 👤 Satoru Yabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 19:42
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/40; H10D86/471; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/13378; G02F1/1345; G02F1/13454; G02F1/136; G02F1/1362; G02F1/136213; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3648; H10D86/60; G02F2202/00; G02F2202/10; G02F2202/105; G09G2330/00; G09G2330/02; G09G5/00; G09G5/003; G09G5/006
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
57 words
A semi-conductor light valve device comprising an insulating substrate (7) having a semi-conductor thin film (1) over at least a portion thereof, and a pixel array region including a plurality of switch elements (2) for selectively energising a plurality of pixel electrodes (3), characterised in that the semi-conductor thin film comprises a semi-conductor single crystal thin film.
Claim 2
Dependent Claim
108 words
A semi-conductor light valve device comprising an insulating substrate (7) having a semi-conductor thin film (1) over at least a portion thereof, and a pixel array region and a peripheral circuit region, the pixel array region including a plurality of switch elements (2) for selectively energising a plurality of pixel electrodes (3), and the peripheral circuit region including drive means (15, 16) for operating the switch elements for selectively energising the pixel electrodes, characterised in that the semi-conductor thin film comprises a semi-conductor single crystal thin film, and in that at least circuit elements of the peripheral circuit region are formed in the semiconductor single crystal thin film.
Claim 3
Dependent Claim
30 words
A device according to claim 2 characterised in that the insulating substrate (21) and the semiconductor single crystal thin film (23) are fixedly laminated through a stress buffering layer (22).
Claim 4
Dependent Claim
40 words
A device according to claim 2 or 3 characterised in that the circuit elements of the peripheral circuit region comprise a plurality of complimentary type insulated gate field effect thin film transistors made of the semi-conductor single crystal thin film.
Claim 5
Dependent Claim
36 words
A device according to claim 2, 3 or 4 characterised in that the switch elements comprise insulated gate field effect thin film transistors, which are made of semi-conductor polycrystal thin film or semi-conductor amorphous thin film.
Claim 6
Dependent Claim
33 words
A device according to claim 2, 3 or 4 characterised in that the switch elements comprise insulated gate field effect thin film transistors, which are made of the semi-conductor single crystal thin film.
Claim 7
Dependent Claim
100 words
A device according to claim 2, 3 or 4 characterised in that the switch elements comprise insulated gate field effect thin film transistors, each including a source region, a drain region and a channel region, which are made of the semi-conductor single crystal thin film, a gate insulating film laminated over the semi-conductor single crystal thin film, and a gate electrode, with the source region and the drain region being formed apart from the interface between the insulating substrate and the semi-conductor single crystal thin film to give the insulated gate field effect thin film transistors a high breakdown voltage.
Claim 8
Dependent Claim
27 words
A device according to claim 2, 3 or 4 characterised in that the switch elements comprise PN junction diodes formed in the semi-conductor single crystal thin film.
Claim 9
Dependent Claim
70 words
A device according to claim 2, 3 or 4 characterised in that the switch elements comprise insulated gate field effect thin film transistors, each of which has a gate electrode and a pair of impurity diffused regions made of the semi-conductor single crystal thin film, and in that the pixel electrodes corresponding to the paired impurity-diffused regions are formed by an impurity-diffused region in the semiconductor single crystal thin film.
Claim 10
Independent Claim
25 words
A device according to any of claims 2 to 8 characterised in that the pixel electrodes are made of the semi-conductor single crystal thin film.
Claim 11
Independent Claim
28 words
A device according to any of claims 2 to 8 characterised in that the pixel electrodes are made of semi-conductor polycrystal thin film or semi-conductor amorphous thin film.
Claim 12
Independent Claim
27 words
A device according to any of claims 2 to 11 characterised in that the pixel electrodes each have their surface shaped to have regular concavities and convexities.
Claim 13
Dependent Claim
94 words
A process for fabricating a semi-conductor light valve device comprising forming an insulating substrate (7) having a semi-conductor thin film (1) over at least a portion thereof, and forming in a pixel array region of the substrate a plurality of pixel electrodes (3) and a plurality of switch elements (2) for selectively energising the pixel electrodes, characterised in that the semi-conductor thin film and the insulating substrate are wormed as a composite substrate by adhering a semi-conductor single crystal plate to the surface of the insulating substrate and by polishing the single crystal plate.
Claim 14
Dependent Claim
150 words
A process for fabricating a semi-conductor light valve device comprising forming an insulating substrate (7) having a semi-conductor thin film (1) over at least a portion thereof, forming in a pixel array region of the substrate a plurality of pixel electrodes (3) and a plurality of switch elements (2) for selectively energising the pixel electrodes, forming in a peripheral circuit region of the substrate drive means (15, 16) for operating the switch elements for selectively energising the pixel electrodes, and connecting the elements of the peripheral circuit region and the pixel array region electrically, characterised in that the semi-conductor thin film and the insulating substrate are formed as a composite substrate by adhering a semi-conductor single crystal plate to the surface of the insulating substrate and by polishing the single crystal plate, and in that circuit elements of the peripheral circuit region are formed by treating the single crystal plate.
Claim 15
Dependent Claim
47 words
A process according to claim 14 characterised in that the step of forming the composite substrate comprises forming a stress buffering layer on the surface of the single crystal plate or the insulating substrate, and adhering the single crystal plate and the insulating substrate by thermo-compressive bonding.
Claim 16
Dependent Claim
127 words
A process according to claim 14 or 15 characterised in that the step of forming the circuit elements of the peripheral circuit region comprises forming a gate insulating film over the surface of the semi-conductor single crystal thin film by removing the semi-conductor single crystal thin film partially and by subjecting the same to a heat treatment, forming a pattern of pre-determined shape to provide a gate electrode by covering the gate insulating film with a thin film of a polycrystal semi-conductor or an amorphous semi-conductor, and forming a source region and a drain region by doping the semi-conductor single crystal thin film with an impurity through the gate electrode acting as a mask to form insulated gate field effect thin film transistors as the circuit elements.
Claim 17
Dependent Claim
123 words
A process according to claim 14, 15 or 16 characterised in that the step of forming the switch elements comprises forming an overall thickness field oxide film by thermally oxidising the overall thickness of a selected area of the semi-conductor single crystal thin film, forming a gate oxide film by thermally oxidising the surface portion of the semi-conductor single crystal thin film which is enclosed by the field oxide film, forming a gate electrode having a pre-determined shape over the oxide film, and forming a source region and a drain region by doping the semi-conductor single crystal thin film with an impurity through the gate electrode acting as a mask, to form insulated gate field effect thin film transistors as the switch elements.
Claim 18
Dependent Claim
49 words
A process according to claim 14, 15 or 16 characterised in that the step of forming the switch elements comprises forming an island region by patterning the semi-conductor single crystal thin film, and forming a PN junction diode by doping a portion of the island region with an impurity.
Claim 19
Dependent Claim
136 words
A process according to claim 14, 15 or 16 characterised in that the step of forming the switch elements and the pixel electrodes comprises forming the pixel electrodes and electrodes of the switch elements continuously by patterning the semi-conductor single crystal thin film into a pre-determined shape, forming a gate insulating film by thermally oxidising the surface of the semi-conductor single crystal thin film and then forming a gate electrode of a pre-determined shape over the gate insulating film, and forming the switch elements as insulated gate field effect thin film transistors and the pixel electrodes at a common step by doping the semi-conductor single crystal thin film with an impurity through the gate electrode acting as a mask to form a source region, a drain region, and the pixel electrode contiguous to the drain region.
Claim 20
Dependent Claim
40 words
A process according to any of claims 14 to 18 characterised in that the step of forming the pixel electrodes comprises depositing and patterning a semi-conductor polycrystal thin film to produce the pixel electrodes from the semi-conductor polycrystal thin film.
References Cited (Backward Citations)
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