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US5157470A
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Thin film transistor, manufacturing method thereof and matrix circuit board and image display device each using the same
Assignee: Hitachi Ltd
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Filing: 1991-05-21
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Granted: 1992-10-20
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Expires: 2011-05-21
Abstract
Abstract Disclosed are a thin film transistor comprising a first electrode pattern formed on an insulating substrate as a gate electrode, a first insulating film formed as a gate insulating film and covering at least the electrode pattern, a semiconductor thin film pattern mainly composed of silicon formed on the insulating film, the semiconductor thin film pattern overlapping the first electrode pattern and the existing region thereof being limited, second and third electrodes formed on the semiconductor thin film pattern as a drain electrode and a source electrode, the second and third electrodes covering a portion of the semiconductor thin film pattern and being spaced apart each other, and a thin film containing silicon oxide formed over the semiconductor film, the second and third electrodes being formed upon the silicon oxide film, a method of manufacturing the thin film transistor, an active matrix circuit board using the thin film transistors, and an image display device using the active matrix circuit board.
Inventors
- 👤 Eiji Matsuzaki
- 👤 Takao Takano
- 👤 Toshiyuki Koshita
- 👤 Yoshifumi Yoritomi
- 👤 Akihiro Kenmotsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:16
CPC Classifications
H; H10; H10D; H10D86/00; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/1368
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
141 words
A thin film transistor, comprising: a first electrode pattern as a gate electrode provided on an insulating substrate; a first insulating film as a gate insulating film provided on said first electrode pattern and a part of said insulating substrate; a semiconductor thin film pattern mainly composed of silicon and provided on a part of said first insulating film, said semiconductor thin film pattern spatially overlapping said first electrode pattern and having a thin silicon oxide layer which contains silicon oxide and which is provided on a surface of at least a part of said semiconductor thin film pattern, said thin silicon oxide layer being a tunneling oxide layer; and second and third electrodes respectively formed on said thin silicon oxide layer as a drain electrode and a source electrode, said second and third electrodes being spaced apart from each other.
Claim 2
Dependent Claim
141 words
A thin film transistor, comprising: a first electrode pattern as a gate electrode provided on an insulating substrate; a first insulating film as a gate insulating film provided on said first electrode pattern and a part of said insulating substrate; a semiconductor thin film pattern mainly composed of silicon and provided on a part of said first insulating film, said semiconductor thin film pattern spatially overlapping said first electrode pattern and having a thin silicon oxide layer which contains silicon oxide and which is provided on a surface of at least a part of said semiconductor thin film pattern, said thin silicon oxide layer being a tunneling oxide layer; and second and third electrodes respectively formed on said thin silicon oxide layer as a drain electrode and a source electrode, said second and third electrodes being spaced apart from each other.
Claim 3
Dependent Claim
82 words
An active matrix circuit board, comprising: a plurality of thin film transistors according to claim 1, which are formed on said insulating substrate in a matrix shape; a first bus line interconnecting said first electrodes of some of said plurality of thin film transistors to be formed on the same rows; and a second bus line interconnecting one of said second electrodes and said third electrodes in some of said plurality of thin film transistors to be formed on the same columns.
Claim 4
Dependent Claim
75 words
An image display device, comprising: the active matrix circuit board according to claim 2; display pixel electrodes respectively coupled to the other of said second electrodes and said third electrodes; a common electrode formed in confrontation with said display pixel electrodes; and display cells respectively disposed in the gaps between said display pixel electrodes and said common electrode and respectively having display material sealed therein which changes the status thereof when voltage is applied thereto.
Claim 5
Dependent Claim
21 words
A thin film transistor according to claim 1, wherein said second and third electrodes are provided above said first electrode pattern.
Claim 6
Dependent Claim
37 words
A thin film transistor according to claim 1, wherein a width of said semiconductor thin film pattern is narrower than that of said first electrode pattern by at least a thickness of said semiconductor thin film pattern.
Claim 7
Dependent Claim
39 words
A thin film transistor according to claim 1, wherein said thin silicon oxide layer is provided by performing surface treatment for a semiconductor layer including said semiconductor thin film pattern, prior to forming of said second and third electrodes.
Claim 8
Dependent Claim
25 words
A thin film transistor according to claim 6, wherein said thin silicon oxide layer has a resistivity greater than that said semiconductor thin film pattern.
Claim 9
Dependent Claim
22 words
A thin film transistor according to claim 1, wherein said thin silicon oxide layer passes electrons and prevents positive holes from passing.
Claim 10
Dependent Claim
38 words
A thin film transistor according to claim 1, wherein said thin silicon oxide layer covers surfaces of said semiconductor thin film pattern except for a portion where said semiconductor thin film pattern contacts with said first insulating film.
Claim 11
Dependent Claim
63 words
A thin film transistor according to claim 1, wherein said thin silicon oxide layer covers surface of said semiconductor thin film pattern, except for a portion where said semiconductor thin film pattern contacts with said first insulating film, and except for a portion where at least one of said second and third electrodes extends to directly contact with said semiconductor thin film pattern.
Claim 12
Dependent Claim
55 words
A thin film transistor according to claim 1, wherein the second and third electrodes are positioned such that current passing between the second electrode and the semiconductor thin film pattern, and between the third electrode and the semiconductor thin film pattern, when the transistor is in an on-state, passes through the thin silicon oxide layer.
Claim 13
Dependent Claim
40 words
A thin film transistor according to claim 11, wherein the thin silicon oxide layer is adapted to act as a blocking film against positive holes so as to make a current, when the transistor is in an off-state, relatively small.
Claim 14
Dependent Claim
51 words
A thin film transistor according to claim 1, wherein the thin silicon oxide layer is provided directly in contact with the semiconductor thin film pattern; and each of the second and third electrodes are provided directly in contact with the thin silicon oxide layer, at locations overlying the first electrode pattern.
Claim 15
Dependent Claim
42 words
A thin film transistor according to claim 1, wherein said thin silicon oxide layer is a layer formed by a surface oxidation process of a semiconductor layer so as to form said thin silicon oxide layer and said semiconductor thin film pattern.
Claim 16
Dependent Claim
22 words
The thin film transistor according to claim 1, wherein said silicon oxide is represented by SiOx (wherein x satisfies the equation 1.5≦x≦2).
Claim 17
Dependent Claim
33 words
The thin film transistor according to claim 15, wherein said thin film containing silicon oxide contains at least one element selected from the group consisting of Group V elements of the periodic table.
Claim 18
Dependent Claim
21 words
The thin film transistor according to claim 1 wherein said thin film containing silicon oxide has a thickness of 0.5-10 nm.
Claim 19
Dependent Claim
25 words
The thin film transistor according to claim 16, wherein the at least one element is selected from the group consisting of P, Sb and As.
Claim 20
Dependent Claim
16 words
The thin film transistor according to claim 18, wherein the at least one element is P.
Claim 21
Dependent Claim
21 words
The thin film transistor according to claim 17, wherein the thin film containing silicon oxide has a thickness of 1.0-3.0 nm.
Claim 22
Dependent Claim
43 words
The thin film transistor according to claim 1, wherein the second and third electrodes are provided upon the thin silicon oxide layer such that the thin silicon oxide layer is provided between the semiconductor thin film pattern and the second and third electrodes.
Claim 23
Dependent Claim
36 words
The thin film transistor according to claim 21, wherein the thin silicon oxide layer is provided such that there is substantially no direct contact between the semiconductor thin film pattern and the second and third electrodes.
Claim 24
Dependent Claim
59 words
The thin film transistor according to claim 1, further comprising a passivating film provided on the semiconductor thin film pattern, said passivating film having through-holes therethrough to the semiconductor thin film pattern, said thin silicon oxide layer being provided in said through-holes, with said second and third electrodes being formed upon said thin silicon oxide layer in said through-holes.
Claim 25
Dependent Claim
23 words
The thin film transistor according to claim 1, wherein said second and third electrodes overlie the first electrode pattern as a gate electrode.
Claim 26
Dependent Claim
20 words
The thin film transistor according to claim 1, wherein the semiconductor thin film pattern is made of an amorphous semiconductor.
Claim 27
Dependent Claim
15 words
The thin film transistor according to claim 25, wherein the amorphous semiconductor is amorphous silicon.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-10-20 | 1996-04-20 | 1996-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-20 | 2000-04-20 | 2000-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-20 | 2004-04-20 | 2004-10-20 | $7700.00 | Window Closed / Lapsed |