US5506165A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing liquid-crystal display panel
Assignee: Panasonic Liquid Crystal Display Co Ltd
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Filing: 1995-03-15
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Granted: 1996-04-09
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Expires: 2015-03-15
Abstract
Abstract To prevent occurrence of a breakdown in the drains of thin-film transistors formed in a display area, without an increase in the number of manufacturing steps required for a conventional manufacturing method. When the source and drain regions of each MOS transistor in a display area are formed by impurity implantation using its gate electrode as a mask, the side walls of the gate electrode across the channel are covered with a mask provided together with the mask for covering the MOS transistors of one type of the complementary MOS transistors in an area outside the display area.
Inventors
- 👤 Toshihiro Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:42
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/01; H10D86/021; H10D86/0231; H10D86/0221; H10D86/40; H10D86/441; H10D86/60
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
199 words
A method of manufacturing a liquid-crystal display panel, comprising the steps of: forming gate electrodes of MOS transistors corresponding to individual pixels in a display area on a transparent plate, said gate electrodes overlying a channel-forming region of said MOS transistors, and having opposed side walls; forming gate electrodes of complementary MOS transistors, the complementary MOS transistors including a first group of MOS transistors and a second group of MOS transistors, wherein the gate electrodes of the complementary MOS transistors are formed in an area outside said display area on said transparent plate; forming a mask for covering a location of said first group of MOS transistors; forming a mask for covering at least the opposed side walls of the gate electrodes of said MOS transistors in said display area, said mask for covering at least the opposed side walls being formed together with said mask for covering said location of said first group of MOS transistors; and forming source regions and drain regions of said MOS transistors in said display area by impurity ion implantation using said mask for covering at least the opposed side walls of the gate electrodes of said MOS transistors in said display area.
Claim 2
Independent Claim
199 words
A method of manufacturing a liquid-crystal display panel, comprising the steps of: forming gate electrodes of MOS transistors corresponding to individual pixels in a display area on a transparent plate, said gate electrodes overlying a channel-forming region of said MOS transistors, and having opposed side walls; forming gate electrodes of complementary MOS transistors, the complementary MOS transistors including a first group of MOS transistors and a second group of MOS transistors, wherein the gate electrodes of the complementary MOS transistors are formed in an area outside said display area on said transparent plate; forming a mask for covering a location of said first group of MOS transistors; forming a mask for covering at least the opposed side walls of the gate electrodes of said MOS transistors in said display area, said mask for covering at least the opposed side walls being formed together with said mask for covering said location of said first group of MOS transistors; and forming source regions and drain regions of said MOS transistors in said display area by impurity ion implantation using said mask for covering at least the opposed side walls of the gate electrodes of said MOS transistors in said display area.
Claim 3
Dependent Claim
44 words
A method of manufacturing a liquid-crystal display panel according to claim 1, wherein one group of the first and second groups of said complementary MOS transistors is n-type MOS transistors, and the other group of the first and second groups is p-type MOS transistors.
Claim 4
Dependent Claim
47 words
A method of manufacturing a liquid-crystal display panel according to claim 2, wherein source and drain regions of said second group of MOS transistors are formed by impurity ion implantation, together with said forming source regions and drain regions of said MOS transistors in said display area.
Claim 5
Dependent Claim
84 words
A method of manufacturing a liquid-crystal display panel according to claim 3, including the further steps of forming a further mask covering a location of said MOS transistors in said display areas and a location of said second group of MOS transistors; and forming source and drain regions of said first group of MOS transistors by ion impurity implantation with said further mask covering said location of said MOS transistors in said display area and said location of said second group of MOS transistors.
Claim 6
Dependent Claim
58 words
A method of manufacturing a liquid-crystal display panel according to claim 4, wherein, prior to said forming the further mask, the mask for covering said location of said first group of MOS transistors and the mask for covering at least the opposed side walls of the gate electrodes of said MOS transistors in said display area are removed.
Claim 7
Dependent Claim
97 words
A method of manufacturing a liquid-crystal display panel according to claim 5, wherein said mask for covering at least the opposed side walls of the gate electrodes and said mask for covering said location of said first group of MOS transistors are made from a photoresist material, and are formed by forming a photoresist film overlying the transparent plate and selectively removing the photoresist film so as to leave said mask for covering at least the opposed side walls of the gate electrodes and said mask for covering said location of said first group of MOS transistors.
Claim 8
Dependent Claim
67 words
A method of manufacturing a liquid-crystal display panel according to claim 1, wherein said mask for covering at least the opposed side walls of the gate electrodes of said MOS transistors in said display area extend away from sides of the gate electrodes, so as to provide source regions and drain regions, by said impurity ion implantation, that are offset from the sides of the gate electrodes.
Claim 9
Dependent Claim
45 words
A method of manufacturing a liquid-crystal display panel according to claim 1, wherein, after said forming source regions and drain regions of said MOS transistors in said display area, said mask for covering at least the opposed side walls of the gate electrodes is removed.
Claim 10
Dependent Claim
97 words
A method of manufacturing a liquid-crystal display panel according to claim 1, wherein said mask for covering at least the opposed side walls of the gate electrodes and said mask for covering said location of said first group of MOS transistors are made from a photoresist material, and are formed by forming a photoresist film overlying the transparent plate and selectively removing the photoresist film so as to leave said mask for covering at least the opposed side walls of the gate electrodes and said mask for covering said location of said first group of MOS transistors.
Claim 11
Dependent Claim
47 words
A method of manufacturing a liquid-crystal display panel according to claim 1, wherein source and drain regions of said second group of MOS transistors are formed by impurity ion implantation, together with said forming source regions and drain regions of said MOS transistors in said display area.
Claim 12
Dependent Claim
48 words
A method of manufacturing a liquid-crystal display panel according to claim 1, wherein the mask for covering at least the opposed side walls of the gate electrodes of the MOS transistors in said display area also covers said gate electrodes of the MOS transistors in said display area.
Claim 13
Dependent Claim
31 words
A method of manufacturing a liquid-crystal display panel according to claim 1, wherein the number of the gate electrodes of each of said MOS transistors in said display area is two.
Claim 14
Dependent Claim
90 words
A method of manufacturing a liquid-crystal display panel according to claim 1, wherein said gate electrodes are formed overlying a semiconductor layer, the source and drain regions of said MOS transistors in said display area being formed in said semiconductor layer, and wherein said mask for covering the opposed side walls of said gate electrodes of said MOS transistors in said display area extends a distance of at least 1.5 μm away from sides of said gate electrodes formed by said side walls, so as to cover said semiconductor layer.
Claim 15
Dependent Claim
35 words
A method of manufacturing a liquid-crystal display panel according to claim 1, wherein the MOS transistors in the display area are of an opposite conductivity type to that of the first group of MOS transistors.
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) | 1999-04-09 | 1999-10-09 | 2000-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-09 | 2003-10-09 | 2004-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-09 | 2007-10-09 | 2008-04-09 | $7700.00 | Window Closed / Lapsed |