Oxide sintered body and an oxide film obtained by using it, and a transparent base material containing it
The oxide sintered body mainly consists of gallium, indium, and oxygen, and a content of the gallium is more than 65 at. % and less than 100 at. % with respect to all metallic elements, and the density of the sintered body is 5.0 g/cm 3 or more. The oxide film is obtained using the oxide sintered body as a sputtering target, and the shortest wavelength of the light where the light transmittance of the film itself except the substrate becomes 50% is 320 nm or less. The transparent base material is obtained by forming the oxide film on one surface or both surfaces of a glass plate, a quartz plate, a resin plate or resin film where one surface or both surfaces are covered by a gas barrier film, or on one surface or both surfaces of a transparent plate selected from a resin plate or a resin film where the gas barrier film is inserted in the inside.
1. An oxide sintered body consisting essentially of gallium, indium, and oxygen, such that:
a content of the gallium is more than 65 at. % and less than 100 at. % with respect to all metallic elements;
the oxide sintered body having one or more phases selected from a gallium oxide phase having β-Ga 2 O 3 type structure (β-Ga 2 O 3 phase), a gallium indium oxide phase having β-Ga 2 O 3 type structure (β-GaInO 3 phase), or (Ga, In) 2 O 3 phase;
the oxide sintered body having an indium oxide phase (In 2 O 3 phase) of bixbyite-type structure; and
a density of the sintered body is 5.0 g/cm 3 or more,
wherein a film can be formed by a direct current sputtering method when the oxide sintered body is used as a sputtering target, and
wherein a ratio in which the indium oxide phase (In 2 O 3 phase) of the bixbyite-type structure contained is 5% or less in terms of an X-ray diffraction peak intensity ratio defined by the following formula (1):
In 2 O 3 phase (400)/{β-Ga 2 O 3 phase (−202)+β-GaInO 3 phase (111)+(Ga,In) 2 O 3 phase (2θ≈33°)}×100 [%] (1).
2. The oxide sintered body according to claim 1 , wherein a content of the gallium is more than 65 at. % and 90 at. % or less with respect to all metallic elements, and a density of the sintered body is 5.5 g/cm 3 or more.
3. The oxide sintered body according to claim 1 or 2 , which is sintered by a hot pressing method under conditions where a sintering temperature is from 800° C.˜1000° C. and a sintering pressure is from 4.9 MPa˜29.4 MPa in an inert gas atmosphere, and a metal indium phase is not contained.