Method of manufacturing a liquid crystal display device with a semiconductor film including zinc oxide
View Patent ↗To provide a semiconductor device in which a defect or fault is not generated and a manufacturing method thereof even if a ZnO semiconductor film is used and a ZnO film to which an n-type or p-type impurity is added is used for a source electrode and a drain electrode. The semiconductor device includes a gate insulating film formed by using a silicon oxide film or a silicon oxynitride film over a gate electrode, an Al film or an Al alloy film over the gate insulating film, a ZnO film to which an n-type or p-type impurity is added over the Al film or the Al alloy film, and a ZnO semiconductor film over the ZnO film to which an n-type or p-type impurity is added and the gate insulating film.
1. A method of manufacturing a liquid crystal display device having an active matrix portion, the method comprising:
forming a metal film over a first substrate;
forming a conductive film comprising an oxide over and in contact with the metal film;
forming a semiconductor film containing zinc oxide as a channel formation region, over and in contact with the conductive film;
removing a portion of the conductive film, wherein the portion is out of contact with the semiconductor film prior to removing the portion;
forming a closed pattern of a sealant around the active matrix portion;
dropping liquid crystal composition in the closed pattern; and
attaching the first substrate and a second substrate to each other after dropping the liquid crystal composition.
2. A method of manufacturing a liquid crystal display device according to claim 1 , wherein the metal film is aluminum film or aluminum alloy film.
3. A method of manufacturing a liquid crystal display device according to claim 1 , wherein the conductive film comprises zinc oxide.
4. A method of manufacturing a liquid crystal display device according to claim 1 , wherein the metal film is a Ti film.
5. A method of manufacturing a liquid crystal display device according to claim 1 , wherein the metal film includes a first metal layer comprising aluminum and a second metal layer comprising titanium wherein the second metal layer is in contact with the conductive film.
6. A method of manufacturing a liquid crystal display device comprising:
forming a thin film transistor over a first substrate by the method comprising:
forming a metal film over the first substrate;
forming a conductive film comprising an oxide over and in contact with the metal film;
forming a semiconductor film comprising zinc oxide over and in contact with the conductive film;
forming a gate electrode adjacent to the semiconductor film with a gate insulating film interposed therebetween; and
removing a portion of the conductive film, wherein the portion is out of contact with the semiconductor film prior to removing the portion
forming a pixel electrode over the first substrate wherein the pixel electrode is electrically connected to the thin film transistor;
forming a closed pattern of a sealant over the first substrate;
dropping liquid crystal composition over the pixel electrode in the closed pattern; and
attaching a second substrate to the first substrate with the liquid crystal composition between the first substrate and the second substrate.
7. A method of manufacturing a liquid crystal display device according to claim 6 , wherein the metal film is aluminum film or aluminum alloy film.
8. A method of manufacturing a liquid crystal display device according to claim 6 , wherein the conductive film comprises zinc oxide.
9. A method of manufacturing a liquid crystal display device according to claim 6 , wherein the metal film is a Ti film.
10. A method of manufacturing a liquid crystal display device according to claim 6 , wherein the metal film includes a first metal layer comprising aluminum and a second metal layer comprising titanium wherein the second metal layer is in contact with the conductive film.
11. A method of manufacturing a liquid crystal display device comprising:
forming a thin film transistor over a first substrate by a method comprising:
forming a gate electrode;
forming a gate insulating film formed over the gate electrode;
forming a metal film formed over the first substrate;
forming a conductive film comprising an oxide on and in contact with the metal film;
forming a semiconductor film comprising zinc oxide on and in contact with the conductive film and the gate insulating film interposed therebetween; and
removing a portion of the conductive film, wherein the portion is out of contact with the semiconductor film prior to removing the portion
forming an insulating film comprising a resin material on the semiconductor film;
forming a pixel electrode over the insulating film wherein the pixel electrode is electrically connected to the thin film transistor through a contact hole of the insulating film;
forming a closed pattern of a sealant over the first substrate;
dropping liquid crystal composition over the pixel electrode in the closed pattern; and
attaching a second substrate to the first substrate with the liquid crystal composition between the first substrate and the second substrate.
12. A method of manufacturing a liquid crystal display device according to claim 11 , wherein the metal film is aluminum film or aluminum alloy film.
13. A method of manufacturing a liquid crystal display device according to claim 11 , wherein the conductive film comprises zinc oxide.
14. A method of manufacturing a liquid crystal display device according to claim 11 , wherein the metal film is a Ti film.
15. A method of manufacturing a liquid crystal display device according to claim 11 , wherein the metal film includes a first metal layer comprising aluminum and a second metal layer comprising titanium wherein the second metal layer is in contact with the conductive film.
16. A method of manufacturing a liquid crystal display device comprising:
forming a gate electrode over a first substrate;
forming a gate insulating film over the gate electrode;
forming a metal film over the first substrate;
forming a conductive film comprising an oxide on and in contact with the metal film; and
forming a semiconductor film comprising zinc oxide on and in contact with the conductive film and the gate insulating film;
removing a portion of the conductive film, wherein the portion is out of contact with the semiconductor film prior to removing the portion
forming an insulating film on the semiconductor film;
forming a pixel electrode over the insulating film wherein the pixel electrode is in contact with the conductive film through a contact hole of the insulating film;
forming a closed pattern of a sealant over the first substrate;
dropping liquid crystal composition over the pixel electrode in the closed pattern; and
attaching a second substrate to the first substrate with the liquid crystal composition between the first substrate and the second substrate.
17. A method of manufacturing a liquid crystal display device according to claim 16 , wherein the metal film is aluminum film or aluminum alloy film.
18. A method of manufacturing a liquid crystal display device according to claim 16 , wherein the conductive film comprises zinc oxide.
19. A method of manufacturing a liquid crystal display device according to claim 16 , wherein the metal film is a Ti film.
20. A method of manufacturing a liquid crystal display device according to claim 16 , wherein the metal film includes a first metal layer comprising aluminum and a second metal layer comprising titanium wherein the second metal layer is in contact with the conductive film.
21. A method of manufacturing a liquid crystal display device according to claim 16 , wherein the insulating film comprises a resin.