Method for manufacturing liquid crystal display device

• US 7,439,086 B2
• Filed: 11/05/2004
• Issued: 10/21/2008
• Est. Priority Date: 11/14/2003
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Maekawa, Shinji, Nakamura, Osamu, Yamazaki, Shunpei
• Primary Examiner(s): Lindsay, Jr.; Walter
• Assistant Examiner(s): MUSTAPHA, ABDULFATTAH B
• Application Number:
  US10/576,641
• Publication Number:
  US 20070082443A1
• Time in Patent Office: 1,446 Days
• Field of Search: 438/30, 438/22, 438/478, 257/E27.131
• US Class Current: 438/30
• CPC Class Codes: H01L 2224/04026 Bonding areas specifically adapted for layer connectors
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/293 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48464 the other connecting portion not on the bonding area also being a ball bond, i.e. ball-to-ball
• CPC Class Codes: H01L 2224/83851 being an anisotropic conductive adhesive
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1285 using control of the annealing or irradiation parameters, e.g. using different scanning direction or intensity for different transistors
• CPC Class Codes: H01L 27/1292 using liquid deposition, e.g. printing
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/66765 Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01077 : Iridium [Ir]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/04941 : TiN
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding

Abstract

A conventionally followed technique of manufacturing a liquid crystal display device is a method for forming various types of coatings over an entire surface of a substrate and for removing the coatings with a small region left by etching, which requires wasting a material cost and treating a large quantity of waste. A liquid crystal display device is manufactured by forming at least one or more of patterns necessary for manufacturing a liquid crystal display device by a method capable of selectively forming a pattern. A droplet discharge method capable of forming a predetermined pattern by selectively discharging a droplet of a composition prepared for a specific purpose is employed as the method capable of selectively forming a pattern.

Claims

1. A method for manufacturing a liquid crystal display device, comprising the steps of:

forming a layer including a photocatalytic substance over a substrate;

forming a gate electrode over the layer including the photocatalytic substance;

forming a first insulating film to cover the gate electrode;

forming a pixel electrode over the first insulating film;

forming a first semiconductor layer over the first insulating film and the pixel electrode;

forming a second insulating film over the first semiconductor layer to overlap the gate electrode;

forming a second semiconductor layer to cover the second insulating film;

patterning the first and second semiconductor layers into an island shape;

forming source and drain wirings over the second semiconductor layer; and

etching the second semiconductor layer using the source and drain wirings as a mask;

wherein at least one of the gate electrode, the pixel electrode, and the source and drain wirings is formed by a droplet discharge method.

4. The method for manufacturing a liquid crystal display device according to claim 1, wherein the layer including the photocatalytic substance is a TiO₂ layer.

5. The method for manufacturing a liquid crystal display device according to claim 1, wherein the layer including the photocatalytic substance has hydrophilic property.

2. A method for manufacturing a liquid crystal display device, comprising the steps of:

forming a layer including a photocatalytic substance over a substrate;

forming a gate electrode over the layer including the photocatalytic substance;

forming a first insulating film to cover the gate electrode;

forming a first semiconductor layer over the first insulating film;

forming a second insulating film over the first semiconductor layer to overlap the gate electrode;

forming a second semiconductor layer to cover the second insulating film;

pattering the first and second semiconductor layers into an island shape;

forming source and drain wirings over the second semiconductor layer;

etching the second semiconductor layer using the source and drain wirings as a mask;

forming a third insulating film over the source and drain wirings and the first insulating film;

forming an opening in third insulating film; and

forming a pixel electrode over the third insulating film,

wherein the pixel electrode is electrically connected with one of the source and drain wirings through the opening, and

wherein at least one of the gate electrode, the source and drain wirings, and the pixel electrode is formed by a droplet discharge method.

6. The method for manufacturing a liquid crystal display device according to claim 2, wherein the layer including the photocatalytic substance is a TiO₂ layer.

7. The method for manufacturing a liquid crystal display device according to claim 2, wherein the layer including the photocatalytic substance has hydrophilic property.

3. A method for manufacturing a liquid crystal display device, comprising the steps of:

forming a layer including a photocatalytic substance over a substrate;

forming a gate electrode over the layer including the photocatalytic substance;

forming a first insulating film to cover the gate electrode;

forming a pixel electrode over the first insulating film;

forming a first semiconductor layer over the first insulating film and the pixel electrode;

forming a second insulating film over the first semiconductor layer to overlap the gate electrode;

forming a second semiconductor layer to cover the second insulating film;

patterning the first and the second semiconductor layers into an island shape;

forming source and drain wirings over the second semiconductor layer;

etching the second semiconductor layer using the source and drain wirings as a mask; and

forming a third insulating film over the source and drain wirings and the pixel electrode,

wherein the pixel electrode is electrically connected with one of the source and drain wirings, and

wherein at least one of the gate electrode, the pixel electrode, and the source and drain wirings is formed by a droplet discharge method.

8. The method for manufacturing a liquid crystal display device according to claim 3, wherein the layer including the photocatalytic substance is a TiO₂ layer.

9. The method for manufacturing a liquid crystal display device according to claim 3, wherein the layer including the photocatalytic substance has hydrophilic property.