An epitaxial rare earth oxide (001)/silicon (001) structure is realized by epitaxially
growing a rare earth oxide such as cerium dioxide in the (001) orientation on a
(001)-oriented silicon substrate. For this purpose, the surface of the (001)-oriented
Si substrate is processed into a dimer structure by 21, 12 surface
reconstruction, and a rare earth oxide of a cubic system or a tetragonal system,
such as CeO2 film, is epitaxially grown in the (001) orientation on
the Si substrate by molecular beam epitaxy, for example. During this growth, a
source material containing at least one kind of rare earth element is supplied
after the supply of an oxidic gas is supplied onto the surface of the Si substrate.
If necessary, annealing is conducted in vacuum after the growth.