Patent ID: 8871119

Claim:
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 μm or less, and a bulk resistance of 30 mΩ2 cm or less, and having a number of tin oxide aggregate particles having a diameter of 10 μm or more being 2.5 or less per mm 2 , wherein the composite oxide sintered body does not comprise a hexagonal layered compound shown by In 2 O 3 (ZnO) 7 and the atomic ratio of In, Zn, and Sn satisfies the following expressions: 0.20<In/(In+Sn+Zn)<0.75 0.50≦Zn/(In+Sn+Zn)≦0.75, and 0.05<Sn/(In+Sn+Zn)<0.50.