US4679062A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film transistor
Assignee: Philips Components Kobe KK
•
Filing: 1985-12-16
•
Granted: 1987-07-07
•
Expires: 2005-12-16
Abstract
Abstract An impurity-doped amorphous silicon semiconductor layer is deposited on a substrate, source and drain electrodes are deposited apart from each other on the amorphous silicon semiconductor layer in ohmic contact therewith and a gate electrode is deposited on the amorphous silicon semiconductor layer in Schottky contact therewith between the source and drain electrodes, thereby forming a thin film transistor.
Inventors
- 👤 Kotaro Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:12
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/40; H10D30/00; H10D30/80; H10D30/87; H10D30/875; H10D86/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
94 words
A thin film transistor comprising: a substrate; an impurity-doped hydrogenated amorphous silicon semiconductor layer formed on the substrate; a source and drain electrode formed apart from one another on the amorphous silicon semiconductor layer in ohmic contact therewith; a gate electrode formed on the amorphous silicon semiconductor layer in Schottky contact therewith between the source and drain electrodes, the portion of said amorphous silicon semiconductor layer underlying the gate electrode being 0.1 to 1.0 μm thick; and an impurity-undoped amorphous silicon semiconductor layer interposed between the impurity-doped amorphous silicon semiconductor layer and the substrate.
Claim 2
Dependent Claim
94 words
A thin film transistor comprising: a substrate; an impurity-doped hydrogenated amorphous silicon semiconductor layer formed on the substrate; a source and drain electrode formed apart from one another on the amorphous silicon semiconductor layer in ohmic contact therewith; a gate electrode formed on the amorphous silicon semiconductor layer in Schottky contact therewith between the source and drain electrodes, the portion of said amorphous silicon semiconductor layer underlying the gate electrode being 0.1 to 1.0 μm thick; and an impurity-undoped amorphous silicon semiconductor layer interposed between the impurity-doped amorphous silicon semiconductor layer and the substrate.
Claim 3
Dependent Claim
60 words
A thin film transistor according to claim 1 wherein a groove is cut in the impurity-doped amorphous silicon semiconductor layer between the source and drain electrodes, the gate electrode is formed on the bottom of the groove, and that portion of the impurity-doped semiconductor layer underlying the gate electrode is thinner than those portions underlying the source and drain electrodes.
Claim 4
Dependent Claim
129 words
A thin film transistor for use as an active element of a drive circuit formed on a transparent substrate for driving switching elements to select picture element electrodes of an active matrix liquid crystal display cell, the thin film transistor comprising: an impurity-doped hydrogenated amorphous silicon semiconductor layer formed on the transparent substrate; a source and a drain electrode formed apart from one another on the amorphous silicon semiconductor layer in ohmic contact therewith; a gate electrode formed on the amorphous silicon semiconductor layer in Schottky contact therewith between the source and drain electrodes, that portion of the amorphous silicon layer underlying the gate electrode being 0.1 to 1.0 μm thick; and an impurity-undoped amorphous silicon semiconductor layer interposed between the impurity-doped amorphous silicon semiconductor layer and the substrate.
Claim 5
Dependent Claim
129 words
A thin film transistor for use as an active element of a drive circuit formed on a transparent substrate for driving switching elements to select picture element electrodes of an active matrix liquid crystal display cell, the thin film transistor comprising: an impurity-doped hydrogenated amorphous silicon semiconductor layer formed on the transparent substrate; a source and a drain electrode formed apart from one another on the amorphous silicon semiconductor layer in ohmic contact therewith; a gate electrode formed on the amorphous silicon semiconductor layer in Schottky contact therewith between the source and drain electrodes, that portion of the amorphous silicon layer underlying the gate electrode being 0.1 to 1.0 μm thick; and an impurity-undoped amorphous silicon semiconductor layer interposed between the impurity-doped amorphous silicon semiconductor layer and the substrate.
Claim 6
Dependent Claim
32 words
A thin film transistor according to claim 1 or claim 3 wherein the impurity concentration of the hydrogenated amorphous silicon layer is in the range of 0.75×10 -3 to 1.5×10 -3 .
Claim 7
Dependent Claim
20 words
A thin film transistor according to claim 4 wherein the impurity doped in the hydrogenated amorphous silicon layer is phosphorus.
Claim 8
Dependent Claim
30 words
A thin film transistor according to claim 1 or claim 3 wherein that portion of the amorphous silicon semiconductor layer underlying the gate electrode is 0.3 to 0.5 μm thick.
Claim 9
Dependent Claim
19 words
A thin film transistor according to claim 1 or claim 3 wherein the gate electrode is formed of gold.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-06 | 1991-01-05 | 1991-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-06 | 1995-01-05 | 1995-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-06 | 1999-01-05 | 1999-07-07 | $7700.00 | Window Closed / Lapsed |