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

• US 7,977,169 B2
• Filed: 02/09/2007
• Issued: 07/12/2011
• Est. Priority Date: 02/15/2006
• Status: Expired due to Fees

• 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
• Primary Examiner(s): Pizarro; Marcos D.
• Assistant Examiner(s): Montalvo; Eva Y.
• Application Number:
  US11/704,838
• Publication Number:
  US 20070187678A1
• Time in Patent Office: 1,614 Days
• Field of Search: 438/150, 438/168, 438/187, 438/198
• US Class Current: 438/150
• 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 manufacturing method of a semiconductor device comprising:

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

wherein forming the oxide semiconductor thin film layer comprises applying a first radio frequency electric power to the oxide target and applying a second radio frequency electric power, which is different from the first radio frequency electric power, to the substrate in order to control an orientation of zinc oxide that is a constituent of the oxide semiconductor thin film layer to have at least one orientation other than (002) orientation.

2. The manufacturing method of a semiconductor device of claim 1, wherein applying the second radio frequency electric power to the substrate is performed via a substrate stage on which the substrate is mounted.

3. The manufacturing method of a semiconductor device of claim 1, wherein a frequency of the first radio frequency electric power is equal to a frequency of the second radio frequency electric power.

4. The manufacturing method of a semiconductor device of claim 1, wherein the sputtering is magnetron sputtering.

5. A manufacturing method of a semiconductor device comprising:

preparing a target used in forming an oxide semiconductor of the semiconductor device;

preparing a substrate; and

forming the oxide semiconductor on the substrate by sputtering using the target;

wherein forming the oxide semiconductor on the substrate comprises applying a first radio frequency electric power to the target and applying a second radio frequency electric power, which is in a range of 0.5% to 45% of the first radio frequency electric power, to the substrate.

6. The manufacturing method of a semiconductor device of claim 5, wherein the target contains zinc oxide, and the second radio frequency electric power is applied such that zinc oxide contained in the oxide semiconductor formed on the substrate has at least one orientation other than (002) orientation.

7. The manufacturing method of a semiconductor device of claim 6, wherein the second radio frequency electric power is applied such that the zinc oxide contained in the oxide semiconductor formed on the substrate has a mixed orientation including (002) orientation and (101) orientation.

8. The manufacturing method of a semiconductor device of claim 6, wherein the second radio frequency electric power is applied such that the zinc oxide contained in the oxide semiconductor formed on the substrate has a mixed orientation including (100) orientation and (101) orientation.

9. The manufacturing method of a semiconductor device of claim 5, wherein a frequency of the first radio frequency electric power is equal to a frequency of the second radio frequency electric power.

10. The manufacturing method of a semiconductor device of claim 5, wherein the sputtering is magnetron sputtering.

11. A manufacturing method of a semiconductor device comprising:

preparing a target containing zinc oxide used in forming an oxide semiconductor of the semiconductor device;

preparing a substrate; and

forming the oxide semiconductor on the substrate by sputtering using the target;

wherein forming the oxide semiconductor on the substrate comprises applying a first radio frequency electric power to the target and applying a second radio frequency electric power, which is smaller than the first radio frequency electric power, to the substrate; and

wherein the second radio frequency electric power is applied such that zinc oxide contained in the oxide semiconductor formed on the substrate has a mixed orientation including (002) orientation and (001) orientation, and 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 formed on the substrate and X-ray diffraction intensity I(101) indicating the (101) orientation of the zinc oxide contained in the oxide semiconductor formed on the substrate is not more than 2.

12. A manufacturing method of a semiconductor device comprising:

preparing a target containing zinc oxide used in forming an oxide semiconductor of the semiconductor device;

preparing a substrate; and

forming the oxide semiconductor on the substrate by sputtering using the target;

wherein forming the oxide semiconductor on the substrate comprises applying a first radio frequency electric power to the target and applying a second radio frequency electric power, which is smaller than the first radio frequency electric power, to the substrate; and

wherein the second radio frequency electric power is applied such that zinc oxide contained in the oxide semiconductor formed on the substrate has a mixed orientation including (100) orientation and (101) orientation, and 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 formed on the substrate and X-ray diffraction intensity I(100) indicating the (100) orientation of the zinc oxide contained in the oxide semiconductor formed on the substrate is in a range of 0.5 to 5.