Semiconductor device including active layer made of zinc oxide with controlled orientations and manufacturing method thereof

• US 20070187678A1
• Filed: 02/09/2007
• Published: 08/16/2007
• Est. Priority Date: 02/15/2006
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited, Kochi Industrial Promotion Center
• Original Assignee: Casio Computer Company Limited, Kochi Industrial Promotion Center
• Inventors: Furuta, Hiroshi, Hirao, Takashi, Matsuda, Tokiyoshi, Hiramatsu, Takahiro, Furuta, Mamoru
• Granted Patent: US 7,977,169 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02491 Conductive materials
• CPC Class Codes: H01L 21/02494 Structure
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02595 polycrystalline
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78693 the semiconducting oxide being amorphous

Abstract

A semiconductor device includes an oxide semiconductor thin film layer primarily including zinc oxide having at least one orientation other than (002) orientation. The zinc oxide may have a mixed orientation including (002) orientation and (101) orientation. Alternatively, the zinc oxide may have a mixed orientation including (100) orientation and (101) orientation.

Claims

1. A semiconductor device comprising an oxide semiconductor thin film layer primarily comprising zinc oxide having at least one orientation other than (002) orientation.

2. The semiconductor device of claim 1, wherein the zinc oxide has a mixed orientation including (002) orientation and (101) orientation.

3. The semiconductor device of claim 2, wherein a ratio I(002)/I(101) between X-ray diffraction intensity I(002) indicating the (002) orientation of the zinc oxide and X-ray diffraction intensity I(101) indicating the (101) orientation of the zinc oxide is not more than 2.

4. The semiconductor device of claim 1, wherein the zinc oxide has a mixed orientation including (100) orientation and (101) orientation.

5. The semiconductor device of claim 4, wherein a ratio I(101)/I(100) between X-ray diffraction intensity I(101) indicating the (101) orientation of the zinc oxide and X-ray diffraction intensity I(100) indicating the (100) orientation of the zinc oxide is in a range of 0.5 to 5.

6. The semiconductor device of claim 1, wherein the zinc oxide is intrinsic zinc oxide.

7. A semiconductor device comprising:

an oxide semiconductor thin film layer containing zinc oxide having at least one orientation other than (002) orientation;

a gate insulating film covering one surface of the oxide semiconductor thin film layer;

a gate electrode formed on the gate insulating film; and

a pair of source/drain electrodes connected to the oxide semiconductor thin film layer.

8. The semiconductor device of claim 7, wherein the zinc oxide has a mixed orientation including (002) orientation and (101) orientation.

9. The semiconductor device of claim 8, wherein a ratio I(002)/I(101) between X-ray diffraction intensity I(002) indicating the (002) orientation of the zinc oxide and X-ray diffraction intensity I(101) indicating the (101) orientation of the zinc oxide is not more than 2.

10. The semiconductor device of claim 7, wherein the zinc oxide has a mixed orientation including (100) orientation and (101) orientation.

11. The semiconductor device of claim 10, wherein a ratio I(101)/I(100) between X-ray diffraction intensity I(101) indicating the (101) orientation of the zinc oxide and X-ray diffraction intensity I(100) indicating the (100) orientation of the zinc oxide is in a range of 0.5 to 5.

12. The semiconductor device of claim 7, wherein the zinc oxide is intrinsic zinc oxide.

13. A semiconductor device containing intrinsic zinc oxide having a mixed orientation including (002) orientation and (101) orientation.

14. A semiconductor device containing intrinsic zinc oxide having a mixed orientation including (100) orientation and (101) orientation.

15. A manufacturing method of a semiconductor device comprising:

forming an oxide semiconductor thin film layer on a substrate by using an oxide target primarily comprising zinc oxide; and

applying radio frequency electric power to the substrate during the step of forming the oxide semiconductor thin film layer to control an orientation of zinc oxide that is a main constituent of the oxide semiconductor thin film layer to have at least one orientation other than (002) orientation.

16. The manufacturing method of a semiconductor device of claim 15, wherein the step of forming the oxide semiconductor thin film layer is performed using magnetron sputtering, and wherein the step of applying the radio frequency electric power to the substrate is performed via a substrate stage.

17. A manufacturing method of a semiconductor device comprising:

preparing a target used in forming an oxide semiconductor thin film layer of the semiconductor device; and

forming the oxide semiconductor thin film layer on a substrate by magnetron sputtering while applying radio frequency input electric power to the target and applying radio frequency bias electric power that is smaller than the input electric power applied to the substrate.

18. The manufacturing method of a semiconductor device of claim 17, wherein the bias electric power is in a range of about 0.5% to about 45% of the input electric power.

19. The manufacturing method of a semiconductor device of claim 17, wherein the target contains zinc oxide so that the oxide semiconductor thin film layer contains zinc oxide, and the oxide semiconductor thin film layer containing zinc oxide has at least one orientation other than (002) orientation.

20. The manufacturing method of a semiconductor device of claim 19, wherein the zinc oxide contained in the oxide semiconductor thin film layer has a mixed orientation including (002) orientation and (101) orientation.

21. The manufacturing method of a semiconductor device of claim 20, wherein a ratio I(002)/I(101) between X-ray diffraction intensity I(002) indicating the (002) orientation of the zinc oxide contained in the oxide semiconductor thin film layer and X-ray diffraction intensity I(101) indicating the (101) orientation of the zinc oxide contained in the oxide semiconductor thin film layer is not more than 2.

22. The manufacturing method of a semiconductor device of claim 19, wherein the zinc oxide contained in the oxide semiconductor thin film layer has a mixed orientation including (100) orientation and (101) orientation.

23. The manufacturing method of a semiconductor device of claim 22, wherein a ratio I(101)/I(100) between X-ray diffraction intensity I(101) indicating the (101) orientation of the zinc oxide contained in the oxide semiconductor thin film layer and X-ray diffraction intensity I(100) indicating the (100) orientation of the zinc oxide contained in the oxide semiconductor thin film layer is in a range of 0.5 to 5.