Transverse electric-field type liquid crystal display device, process of manufacturing the same, and scan-exposing device

A process of manufacturing a liquid crystal display device of transverse electric-field type including (a) a pair of substrates at least one of which is transparent, (b) a layer of a liquid crystal composition interposed between the pair of substrates, (c) a plurality of scanning lines driven by an external scanning-line driver circuit through scanning-line terminal portions and extending in a line direction, (d) a plurality of image-signal wires extending in a column direction, (e) picture-element electrodes corresponding to respective picture elements, (f) common electrodes cooperating with said picture-element electrodes, and (g) thin-film transistor elements connected to said scanning lines and said image-signal wires, and wherein said scanning lines, said image-signal wires, said picture-element electrodes, said common electrodes and said thin-film transistor elements are provided on a surface of one of said pair of substrates which faces said layer of the liquid crystal composition, said process comprising:

• a first photomasking step of forming a positive resist that covers portions of a semiconductor layer formed on said one substrate, which portions correspond to gate electrodes of said thin-film transistor elements and said common electrodes;
• a second photomasking step which is a halftone exposing step of forming a positive resist that covers portions of said semiconductor layer which correspond to said thin-film transistor elements where the positive resist has a thickness smaller than a positive resist corresponding to the thin-film transistor element formed on the other portion of the substrate, and forming resist-free areas that cover portions of said semiconductor layer which correspond to a first connecting portion, a second connecting portion and a third connecting portion, said first connecting portion being provided to form first static-electricity protective transistor elements connecting said common electrodes and said scanning lines, said second connecting portion being provided to form second static-electricity protective transistor elements connecting said common electrodes and said image-signal wires, and said third connecting portion connecting said external scanning-line driver circuit and said scanning line terminal portions;
• a third photomasking step of forming a positive resist that covers portions of said semiconductor layer which correspond to source electrodes and drain electrodes of said thin-film transistor elements, and said picture-elements electrodes;
• and
• a fourth photomasking step of forming a positive resist for forming contact holes of said scanning-line terminal portions and contact holes of image-signal wire terminal portions.

A process of manufacturing a liquid crystal display device of transverse electric-field type including (a) a pair of substrates at least one of which is transparent, (b) a layer of a liquid crystal composition interposed between the pair of substrates, (c) a plurality of scanning lines driven by an external scanning-line driver circuit through scanning-line terminal portions and extending in a line direction, (d) a plurality of image-signal wires extending in a column direction, (e) picture-element electrodes corresponding to respective picture elements, (f) common electrodes cooperating with said picture-element electrodes, and (g) thin-film transistor elements connected to said scanning lines and said image-signal wires, and wherein said scanning lines, said image-signal wires, said picture-element electrodes, said common electrodes and said thin-film transistor elements are provided on a surface of one of said pair of substrates which faces said layer of the liquid crystal composition, said process comprising:

• a first photomasking step of forming a positive resist that covers portions of a semiconductor layer formed on said one substrate, which portions correspond to gate electrodes of said thin-film transistor elements and said common electrodes;
• a second photomasking step which is a halftone exposing step of forming a positive resist that covers portions of said semiconductor layer which correspond to said thin-film transistor elements where the positive resist has a thickness smaller than a positive resist corresponding to the thin-film transistor element formed on the other portion of the substrate, and forming resist-free areas that cover portions of said semiconductor layer which correspond to a first connecting portion, a second connecting portion and a third connecting portion, said first connecting portion being provided to form first static-electricity protective transistor elements connecting said common electrodes and said scanning lines, said second connecting portion being provided to form second static-electricity protective transistor elements connecting said common electrodes and said image-signal wires, and said third connecting portion connecting said external scanning-line driver circuit and said scanning line terminal portions;
• a third photomasking step of forming a positive resist that covers portions of said semiconductor layer which correspond to source electrodes and drain electrodes of said thin-film transistor elements, and said picture-elements electrodes;
• and
• a passivation step of subjecting a back channel portion of each of said thin-film transistor elements to a plasma doping treatment with a B2H6 gas, and coating said back channel portion with a layer formed of one of BCB, polyphenyl silazane and an organic material by ink-jet coating or flexo graphic printing method.