SINGLE CRYSTAL OXIDE THIN FILM HAVING ROCK CRYSTAL TYPE CRYSTAL STRUCTURE AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To inexpensively produce a single crystal oxide thin film having an arbitrary film thickness and a smooth surface by forming the single crystal oxide thin film on a rock crystal type single crystal substrate. SOLUTION: A precursor soln. containing 20-98mol.% GeO2 , 0-78mol.% SiO2 and 0.05-2mol.% Al or an alkali metal is applied on the rock crystal type single crystal substrate 6 and heated at 300-600 deg.C to form a first intermediate layer 5. Then the precursor soln. containing 20-98mol.% GeO2 , 0-78mol.% SiO2 and 0.05-2mol.% Al or the alkali metal is applied on the first intermediate layer 5 and heated at 750-1100 deg.C to form a second intermediate layer 7. Then, a precursor soln. containing silicon is applied on the second intermediate layer 7 and heated to a stabilizing temp. (750-1200 deg.C) of the rock crystal type crystal structure to form a single crystal oxide thin film 4, and the intermediate layers 5 and 7 are dissolved and removed in water to obtain the single crystal oxide thin film 4 having the rock crystal type single crystal structure having 5-100nm surface roughness.