Fabrication methods of a ZnO thin film structure and a ZnO thin film transistor, and a ZnO thin film structure and a ZnO thin film transistor

• US 20070241327A1
• Filed: 02/05/2007
• Published: 10/18/2007
• Est. Priority Date: 04/18/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Eun-Ha, Park, Young-Soo, Kim, Chang-Jung, Kang, Dong-Hun, Song, I-Hun
• Granted Patent: US 7,919,365 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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

Provided is a method of fabricating a ZnO thin film structure and a ZnO thin film transistor (TFT), and a ZnO thin film structure and a ZnO thin film transistor. The method of fabricating a ZnO thin film structure may include forming a ZnO thin film on a substrate in an oxygen atmosphere, forming oxygen diffusion layers of a metal having an affinity for oxygen on the ZnO thin film and heating the ZnO thin film and the oxygen diffusion layers to diffuse oxygen of the ZnO thin film into the oxygen diffusion layers.

Claims

1. A method of fabricating a zinc oxide (ZnO) thin film structure, comprising:

forming a ZnO thin film on a substrate in an oxygen atmosphere;

forming oxygen diffusion layers on the ZnO thin film using a metal having an affinity for oxygen; and

heating the ZnO thin film and the oxygen diffusion layers to diffuse oxygen of the ZnO thin film into the oxygen diffusion layers.

2. The method of claim 1, wherein forming the ZnO thin film includes using a radio frequency (RF) magnetron sputtering method.

3. The method of claim 1, wherein forming the oxygen diffusion layers includes forming one of Ti, Ta, Ni, and ITO.

4. A method of fabricating a ZnO thin film transistor (TFT) comprising:

forming a semiconductor channel including a ZnO thin film in an oxygen atmosphere;

forming source and drain electrodes including conductive oxygen diffusion layers contacting opposite sides of the semiconductor channel; and

heating the semiconductor channel and the source and drain electrodes to diffuse oxygen of the semiconductor channel into the conductive oxygen diffusion layers to adjust a density of oxygen of the semiconductor channel.

5. The method of claim 4, wherein the conductive oxygen diffusion layers are formed after the ZnO thin film is formed.

6. The method of claim 4, wherein the conductive oxygen diffusion layers are formed before the ZnO thin film is formed.

7. The method of claim 4, wherein the ZnO thin film is formed using an RF magnetron sputtering method.

8. The method of claim 7, wherein the conductive oxygen diffusion layers are formed of one of Ti, Ta, Ni, and ITO.

9. The method of claim 4, wherein the conductive oxygen diffusion layers are formed of one of Ti, Ta, Ni, and ITO.

10. The method of claim 4, wherein forming the source and drain electrodes includes forming first and second layers,

wherein the first layers are the conductive oxygen diffusion layers.

11. A zinc oxide (ZnO) thin film structure, comprising:

a substrate;

a ZnO thin film on the substrate; and

oxygen diffusion layers on the ZnO thin film, the oxygen diffusion layers including a metal having an affinity for oxygen.

12. The method of claim 11, wherein the ZnO thin film is formed using a radio frequency (RF) magnetron sputtering method.

13. The method of claim 11, wherein the oxygen diffusion layers are made of one of Ti, Ta, Ni, and ITO.

14. A ZnO TFT comprising:

a semiconductor channel including a ZnO thin film;

source and drain electrodes including conductive oxygen diffusion layers formed of a metal having an affinity for oxygen and contacting opposite sides of the semiconductor channel;

a gate including an electrical field in the channel; and

a gate insulator between the gate and the semiconductor channel.

15. The ZnO TFT of claim 14, wherein the conductive oxygen diffusion layers are formed of one of Ti, Ta, Ni, and ITO.

16. The ZnO TFT of claim 14, wherein the source and drain electrodes include first layers contacting the semiconductor channel and second layers stacked on the first layers,

wherein the first layers are the conductive oxygen diffusion layers.

17. The ZnO TFT of claim 16, wherein the second layers are formed of Pt.

18. The ZnO TFT of claim 17, wherein the gate is between the semiconductor channel and the substrate.

19. The ZnO TFT of claim 17, wherein the gate is on the semiconductor channel.

20. The ZnO TFT of claim 14, wherein the gate is between the semiconductor channel and the substrate.