Composite oxide sintered body and sputtering target comprising same

• US 8,753,548 B2
• Filed: 12/07/2009
• Issued: 06/17/2014
• Est. Priority Date: 12/12/2008
• Status: Active Grant

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Yano, Koki, Kawashima, Hirokazu
• Primary Examiner(s): Nguyen, Khanh Tuan
• Application Number:
  US13/133,801
• Publication Number:
  US 20110260121A1
• Time in Patent Office: 1,653 Days
• Field of Search: 252/519.51, 174/126.2, 204/192.13, 204/298.13, 257/43, 428/1.1
• US Class Current: 252/519.51
• CPC Class Codes: C04B 35/453 based on zinc, tin, or bismuth oxides or solid solutions thereof with other oxides, e.g. zincates, stannates or bismuthates
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: H01L 21/02403 Oxides
• 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 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02592 amorphous
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 29/2206 Amorphous materials
• 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 composite oxide sintered body includes In, Zn, and Sn, and has a relative density of 90% or more, an average crystal grain size of 10 μm or less, and a bulk resistance of 30 mΩcm or less, the number of tin oxide aggregate particles having a diameter of 10 μm or more being 2.5 or less per mm² of the composite oxide sintered body.

Claims

1. A composite oxide sintered body comprising In, Zn, and Sn, and having a relative density of 90% or more, an average crystal grain size of 10 μ

m or less, a bulk resistance of 30 mΩ

cm or less and a nitrogen content of 5 ppm or less, and having a number of tin oxide aggregate particles having a diameter of 10 μ

m or more being 2.5 or less per mm².

2. The composite oxide sintered body according to claim 1, the composite oxide sintered body having a variation in relative density in a plane direction of 1% or less, and an average hole count of 800 or less per mm².

3. The composite oxide sintered body according to claim 1, wherein the atomic ratio of In, Zn, and Sn satisfies the following expressions:

0<

In/(In+Sn+Zn)<

0.75

0.25≦

Zn/(In+Sn+Zn)≦

0.75, and

0<

Sn/(In+Sn+Zn)<

0.50.

4. A sputtering target comprising the composite oxide sintered body according to claim 1.

5. The sputtering target according to claim 4, wherein metal atoms included in the composite oxide sintered body consist essentially of In, Sn, and Zn, and the ratio of the metal atoms satisfies the following expressions:

0<

In/(In+Sn+Zn)<

0.40,

0.25≦

Zn/(In+Sn+Zn)<

0.70, and

0.05<

Sn/(In+Sn+Zn)<

0.25.

6. An amorphous oxide film obtained by sputtering using the sputtering target according to claim 4 at a film-forming temperature between room temperature and 450°

C., the amorphous oxide film having an electron carrier density of less than 10¹⁸/cm³.

7. A thin film transistor comprising the amorphous oxide film according to claim 6 as a channel layer.