FORMATION OF SINGLE CRYSTAL THIN FILM

PURPOSE:To form a large area single crystal thin film which has few defects due to heating with a heater of energy beam irradiation, a lamp, etc. by using a silicon oxide nitride film as an insulation film between a thin film to be crystallized to single crystal and a substrate. CONSTITUTION:After a silicon oxide nitride film 2 composed of 30-50atom% silicon, 5-50atom% oxygen and 14-53atom% nitrogen is formed on a silicon substrate 1 by reactive sputtering, a polycrystalline silicon film 3 is formed on the silicon oxide nitride film 2 by reduced pressure chemical vapor phase epitaxy, a silicon oxide film 4 is formed on the film 3 by chemical vapor phase epitaxy and a sample is made. If the sample is irradiated with argon laser light and the polycrystalline silicon film 3 is melted and recrystallized to single crystal, the single crystal silicon film has a small strain since the difference of the thermal expansion rates of the silicon oxide nitride film 2 and the polycrystalline silicon film 3 is small. Accordingly, the generation of defective crystal is reduced and good quality and great area single crystal can be obtained.