THIN FILM TRANSISTOR, METHOD OF FABRICATING ACTIVE LAYER THEREOF, AND LIQUID CRYSTAL DISPLAY

• US 20080057631A1
• Filed: 12/22/2006
• Published: 03/06/2008
• Est. Priority Date: 09/04/2006
• Status: Active Grant

• Current Assignee: AU Optronics Corporation, Chunghwa Picture Tubes Limited, HannStar Display Corporation, Industrial Technology Research Institute, Chi Mei Optoelectronics (InnoLux Corporation), TPO Displays Corporation (InnoLux Corporation), Taiwan TFT LCD Association
• Original Assignee: AU Optronics Corporation, Chunghwa Picture Tubes Limited, HannStar Display Corporation, Industrial Technology Research Institute, Chi Mei Optoelectronics (InnoLux Corporation), TPO Displays Corporation (InnoLux Corporation), Taiwan TFT LCD Association
• Inventors: Cheng, Hsiang-Yuan, Yu, Chin-Chih, Chiang, Shin-Chuan, Chuang, Bor-Chuan, Lai, Shih-Hsiang
• Granted Patent: US 7,745,267 B2
• Time in Patent Office: Days
• US Class Current: 438/149
• CPC Class Codes: H01L 27/1292 using liquid deposition, e.g. printing
• CPC Class Codes: H01L 29/78681 having a semiconductor body comprising AIIIBV or AIIBVI or AIVBVI semiconductor materials, or Se or Te
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A manufacturing method of an active layer of a thin film transistor is provided. The method includes following steps. First a substrate is provided, and a semiconductor precursor solution is then prepared through a liquid process. Thereafter, the semiconductor precursor solution is provided on the substrate to form a semiconductor precursor thin film. After that, a light source is used to irradiate the semiconductor precursor thin film to remove residual solvent and allow the semiconductor precursor thin film to produce semiconductor property, so as to form a semiconductor active layer.

Claims

1. A method of fabricating an active layer of a thin film transistor, comprising:

providing a substrate;

preparing a semiconductor precursor solution using a liquid process;

applying the semiconductor precursor solution on the substrate to form a semiconductor precursor thin film; and

irradiating the semiconductor precursor thin film with a light source to remove residual solvent in the semiconductor precursor thin film and transform the semiconductor precursor thin film into an active semiconductor layer having semiconductor property.

2. The method as claimed in claim 1, wherein the light source has a wavelength between 5 nm and 750 nm and an energy between 0.01 mj/cm² and 1200 mj/cm²

3. The method as claimed in claim 1, wherein the liquid process comprises sol-gel, chemical bath deposition, photo-chemical deposition, or evenly distributing semiconductor nano particles into solvent.

4. The method as claimed in claim 1, wherein the step of applying the semiconductor precursor thin film comprises spin-coating, inkjet printing, drop-printing, casting, micro-contact, micro-stamp, or dipping.

5. The method as claimed in claim 1, further comprising a step of performing a soft baking before irradiating the semiconductor precursor thin film with the light source.

6. The method as claimed in claim 1, further comprising a step of removing the semiconductor precursor thin film not irradiated by the light source after forming the semiconductor active layer.

7. The method as claimed in claim 1, further comprising a step of providing a mask after forming the semiconductor precursor thin film to serve as a mask when irradiating the semiconductor precursor thin film with the light source.

8. The method as claimed in claim 1, wherein the semiconductor precursor thin film comprises an II-VI compound semiconductor precursor.

9. The method as claimed in claim 8, wherein the II-VI compound semiconductor precursor comprises ZnO.

10. The manufacturing method as claimed in claim 1, wherein the substrate comprises Si wafer, glass substrate, ceramic substrate, metal substrate, paper substrate, or plastic substrate.

11. A thin film transistor, comprising:

a substrate;

a gate, a source, and a drain, respectively disposed on the substrate;

an insulating layer, disposed on the substrate isolating the gate and the source/drain; and

a semiconductor active layer, connecting the source and the drain, wherein the material of the semiconductor active layer is a semiconductor precursor which produces semiconductor property after being irradiated by a light source.

12. The thin film transistor as claimed in claim 11, wherein the light source has a wavelength between 5 nm and 750 nm and an energy between 0.01 mj/cm² and 1200 mj/cm².

13. The thin film transistor as claimed in claim 11, wherein the semiconductor precursor comprises a II-VI compound semiconductor precursor.

14. The thin film transistor as claimed in claim 13, wherein the II-VI compound semiconductor precursor comprises ZnO.

15. The thin film transistor as claimed in claim 11, further comprising a semiconductor precursor thin film connected to the semiconductor active layer and having the same material as the semiconductor precursor.

16. The thin film transistor as claimed in claim 11, wherein the substrate comprises Si wafer, glass substrate, ceramic substrate, metal substrate, paper substrate, or plastic substrate.

17. The thin film transistor as claimed in claim 11, wherein the source, the drain and the gate respectively comprise metal material, transparent conductive material or organic conductive material.

18. The thin film transistor as claimed in claim 17, wherein metal material comprises Al, Cu, Mo, Ag, or Au.

19. The thin film transistor as claimed in claim 17, wherein transparent conductive material comprises indium tin oxide (ITO) or antimony tin oxide (ATO).

20. The thin film transistor as claimed in claim 17, wherein organic conductive material comprises poly (3,4-ethylenedioxy-thiophene (PEDOT).

21. The thin film transistor as claimed in claim 11, wherein the insulating layer comprises organic insulating material or inorganic insulating material.

22. The thin film transistor as claimed in claim 21, wherein organic insulating material comprises poly (vinyl pyrrolidone) (PVP), polyvinyl alcohol (PVA), poly (methyl methacrylate) (PMMA), or polyimide (PI).

23. The thin film transistor as claimed in claim 21, wherein inorganic insulating material comprises SiOx, SiNx, LiF, or Al₂O₃.

24. A liquid crystal display, comprising:

a display substrate, comprising;

a first substrate;

a first electrode layer, disposed on the first substrate;

a thin film transistor as claimed in claim 11, disposed on the first substrate and electrically connected to the first electrode layer;

a first alignment film, disposed on the first electrode layer;

a counter substrate, comprising;

a second substrate;

a second electrode layer, disposed on the second substrate;

a second alignment film, disposed on the second electrode layer; and

a liquid crystal layer, disposed between the display substrate and the counter substrate.

25. The liquid crystal display as claimed in claim 24, wherein the semiconductor active layer in the thin film transistor comprises a II-VI compound semiconductor layer.

26. The liquid crystal display as claimed in claim 25, wherein the II-VI compound semiconductor layer comprises a ZnO semiconductor layer.

27. The liquid crystal display as claimed in claim 24, wherein the source, the drain, and the gate in the thin film transistor respectively comprise metal material, transparent conductive material or organic conductive material.

28. The liquid crystal display as claimed in claim 27, wherein metal material comprises Al, Cu, Mo, Ag, or Au.

29. The liquid crystal display as claimed in claim 27, wherein transparent conductive material comprises ITO or ATO.

30. The liquid crystal display as claimed in claim 27, wherein organic conductive material comprises PEDOT.

31. The liquid crystal display as claimed in claim 24, wherein the insulating layer of the thin film transistor comprises organic insulating material or inorganic insulating material.

32. The liquid crystal display as claimed in claim 31, wherein organic insulating material comprises PVP, PVA, PMMA, or PI.

33. The liquid crystal display as claimed in claim 31, wherein inorganic insulating material comprises SiOx, SiNx, LiF, or Al₂O₃.