EP0586147A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A semiconductor device and method of manufacture
Assignee: Seiko Instruments Inc
•
Filing: 1993-08-19
•
Granted: —
•
Expires: 2013-08-19
Abstract
Abstract A semiconductor substrate (3) is utilised to integrally form a drive circuit (8) and a pixel array (9) to produce a transparent semiconductor device for a light valve. The semiconductor device for a light valve is constructed by the semiconductor substrate (3) having an opaque portion (1) and a thin transparent portion (2). The pixel array (9) is formed in the transparent portion. The drive circuit (8) is formed in a top face of the opaque portion (1). A transparent support substrate (5) is laminated to the top face of the semiconductor substrate (3) for reinforcement. A bulk of the semiconductor substrate (3) is removed from a back face by selective etching to provide the transparent portion (2).
Inventors
- 👤 Hiroaki C/O Seiko Instruments Inc. Takasu
- 👤 Yoshikazu C/O Seiko Instruments Inc. Kojima
- 👤 Kunihiro C/O Seiko Instruments Inc. Takahashi
- 👤 Tsuneo C/O Seiko Instruments Inc. Yamazaki
- 👤 Tadao C/O Seiko Instruments Inc. Iwaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 12:37
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/40; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1345; G02F1/13454; H10D86/201; H10D86/60; G02F1/136; G02F1/1362; G02F1/136277; G02F1/136281; G02F2202/00; G02F2202/10; G02F2202/105
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
56 words
A semiconductor device for a light valve comprising a substrate (3) having an opaque portion and a transparent portion, a pixel (9) formed on the transparent portion, a drive circuit (8) formed on the opaque portion for driving the pixel, characterised by a transparent support substrate (5) laminated to the substrate over at least the pixel.
Claim 2
Dependent Claim
37 words
A semiconductor device as claimed in claim 1, in which the semiconductor substrate has a monocrystalline silicon layer, and the drive circuit comprises a semiconductor integrated circuit formed in the major face of the monocrystalline silicon layer.
Claim 3
Dependent Claim
34 words
A semiconductor device as claimed in claim 1, in which the semiconductor substrate comprises an SOI wafer having a stacked-structure of a silicon plate and a monocrystalline silicon layer interposed with an insulating film.
Claim 4
Dependent Claim
32 words
A semiconductor device as claimed in claim 2 or 3, in which said opaque portion is formed by the semiconductor substrate being thicker relative to said transparent portion which is relatively thin.
Claim 5
Dependent Claim
48 words
A semiconductor device as claimed in any one of claims 1 to 4, in which there is a plurality of pixels arranged in an active matrix array having pixel electrodes arranged in a matrix and switching elements of the respective drive circuit for selectively driving individual pixel electrodes.
Claim 6
Dependent Claim
36 words
A semiconductor device as claimed in claim 5, in which each switching element comprises any one of a polycrystalline silicon thin film transistor, an amorphous silicon thin film transistor, or a monocrystalline silicon thin film transistor.
Claim 7
Dependent Claim
45 words
A semiconductor device as claimed in claim 6, in which the polycrystalline silicon thin film transistor is formed in a polycrystalline silicon thin film and the pixel electrode is made of the polycrystalline silicon thin film having a thickness in order of 50nm ± 10nm.
Claim 8
Dependent Claim
48 words
A semiconductor device according to any one of the preceding claims, in which the or each drive circuit and the or each pixel comprises concurrently formed field effect type transistors including a field oxide film, a gate oxide film, a gate electrode, a source region and drain region.
Claim 9
Dependent Claim
31 words
A semiconductor device as claimed in any one of the preceding claims, in which the semiconductor substrate has an insulating film (13) disposed as an etching stopper on the transparent portion.
Claim 10
Dependent Claim
40 words
A semiconductor device as claimed in claim 9, in which a thickness of the insulating film in a region where the pixel is formed is smaller than of the insulating film in a region where the drive circuit is formed.
Claim 11
Dependent Claim
36 words
A semiconductor device according to any one of the preceding claims, in which the transparent support substrate is made of a transparent inorganic material having a thermal expansion coefficient comparable to that of the semiconductor substrate.
Claim 12
Dependent Claim
25 words
A semiconductor device as claimed in claim 11, in which the transparent inorganic material is at least one of a glass, a quartz or sapphire.
Claim 13
Dependent Claim
28 words
A semiconductor device as claimed in any one of the preceding claims, further including an adhesive layer (17) interposed between the transparent support substrate and the semiconductor substrate.
Claim 14
Dependent Claim
27 words
A semiconductor layer as claimed in any one of the preceding claims, further including a levelling layer (20) interposed between the adhesive layer and the semiconductor substrate.
Claim 15
Dependent Claim
24 words
A semiconductor device as claimed in claim 13 or 14, in which the adhesive layer and the levelling layer constitute the transparent support substrate.
Claim 16
Dependent Claim
33 words
A semiconductor device as claimed in any one of the preceding claims, in which the transparent portion has a cavity for receiving a counter substrate (16) so as to construct a light valve.
Claim 17
Dependent Claim
35 words
A semiconductor device as claimed in any one of the preceding claims, in which the semiconductor substrate has a light shielding film (84) disposed in registration with at least a part of the drive circuit.
Claim 18
Independent Claim
71 words
A method of producing a semiconductor device for a light valve characterised by: forming a pixel (9) and a drive circuit (8) on a major face of a semiconductor substrate (3); laminating a transparent support substrate (5) on the major face of the semiconductor substrate; and selectively removing a thickness of the semiconductor substrate from a back face opposite to the major face over a portion in registration with the pixel.
Claim 19
Dependent Claim
63 words
A method of producing a semiconductor device as claimed in claim 18, in which forming the pixel and drive circuit includes forming an underlying stopper film (13) on the major face of the semiconductor substrate in registration with the pixel, and removing the thickness includes etching a back face of the semiconductor substrate to remove the thickness thereof to reach the stopper film.
Claim 20
Dependent Claim
86 words
A method of producing a semiconductor device as claimed in claim 19, in which forming the pixel and drive circuit includes forming a first region having a relatively high etching rate in a portion of the semiconductor substrate disposed under the stopper film, and a second region having a relatively low etching rate in another portion of the semiconductor substrate disposed outside the stopper film, and removing the thickness includes applying selective etching to the thickness of the semiconductor substrate, which uses a differential etch rate.
Claim 21
Dependent Claim
55 words
A method of producing a semiconductor device as claimed in claim 20, in which the first region is composed of an impurity region having a density greater than that of the second region, and the selective etching is carried out using an etchant which is a mixture of hydrofluoric acid, nitric acid or acetic acid.
Claim 22
Dependent Claim
42 words
A method of producing a semiconductor device as claimed in claim 20, in which the second region is comprised of an impurity region having a density greater than that of the first region, and the selective etchant includes an alkali etching liquid.
Claim 23
Independent Claim
24 words
A method of producing a semiconductor device as claimed in any one of claims 18 to 22, in which removing the thickness includes grinding.
Claim 24
Independent Claim
59 words
A method of producing a semiconductor device as claimed in any one of claims 19 to 23, in which forming the pixel and drive circuit includes embedding a silicon oxide post (293) into the major face of the semiconductor substrate over a portion outside the stopper film, and removing the thickness includes etching the semiconductor substrate by mechanical-chemical polishing.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.