Oxide thin film, electronic device substrate and electronic device

An oxide thin film in the form of a unidirectionally oriented epitaxial film of the composition:

• Zr.sub.1-x R.sub.x O.sub.2-.delta. wherein R is a rare earth metal inclusive of yttrium, x is a number of 0 to 0.75, and .delta. is a number of 0 to 0.5, formed on a single crystal silicon substrate wherein a rocking curve of reflection on a (002) or (111) plane of said film has a half-value width of up to 1.5.degree., and said film has a ten point mean roughness Rz of up to 0.60 nm across a reference length of 500 nm over at least 80% of its surface.

A substrate for use in electronic devices comprising a single crystal silicon substrate and an oxide thin film in the form of a unidirectionally oriented epitaxial film consisting essentially of ZrO.sub.2 formed on the single crystal silicon substrate, wherein said unidirectionally oriented epitaxial film contains at least 95% of Zr based on the amount of only constituent elements of the film excluding oxygen, a rocking curve of reflection on a (002) or (111) plane of said unidirectionally oriented epitaxial film has a half-value width of up to 1.5.degree., and

• said unidirectionally oriented epitaxial film has a ten point mean roughness Rz of up to 2 nm across a reference length of 500 nm over at least 80% of its surface.

A substrate for use in electronic devices comprising a single crystal silicon substrate and an oxide thin film in the form of an epitaxial film of the composition:

• Zr.sub.1-x R.sub.x O.sub.2-.delta. wherein R is a rare earth metal inclusive of yttrium, x is a number of 0 to 0.75, and .delta. is a number of 0 to 0.5, formed on the single crystal silicon substrate wherein a rocking curve of reflection on a (002) or (111) plane of said film has a half-value width of up to 1.5.degree., and said film has a ten point mean roughness Rz of up to 0.60 nm across a reference length of 500 nm over at least 80% of its surface.

The substrate for use in electronic devices of claim 13 wherein said epitaxial film is a unidirectionally oriented epitaxial film.

A silicon substrate of single crystal silicon whose surface has a 1.times.1 surface structure formed of silicon, oxygen and at least one metal selected from the group consisting of an alkaline earth metal, rare earth metal (inclusive of scandium and yttrium), zirconium, and hafnium.

A semiconductor device comprising a single crystal silicon substrate and an insulating layer formed on said substrate, characterized in that said insulating layer is a unidirectionally oriented epitaxial film consisting essentially of ZrO.sub.2, wherein said unidirectionally oriented epitaxial film contains at least 95% of Zr based on the amount of only constituent elements of the film excluding oxygen, a rocking curve of reflection on a (002) or (111) plane of said unidirectionally oriented epitaxial film has a half-value width of up to 1.5.degree., and

• said unidirectionally oriented epitaxial film has a ten point mean roughness Rz of up to 2 nm across a reference length of 500 nm over at least 80% of its surface.

A semiconductor device comprising a single crystal silicon substrate and an insulating layer formed on said substrate, characterized in that said insulating layer is a unidirectionally oriented epitaxial film of the composition:

• Zr.sub.1-x R.sub.x O.sub.2-.delta. wherein R is a rare earth metal inclusive of yttrium, x is a number of 0 to 0.75, and .delta. is a number of 0 to 0.5, wherein a rocking curve of reflection on a (002) or (111) plane of said film has a half-value width of up to 1.5.degree., and said film has a ten point mean roughness Rz of up to 0.60 nm across a reference length of 500 nm over at least 80% of its surface.