| 摘要 |
PURPOSE:To obtain SOI by forming, on the surface of Si thin film, a film which is not liquified even at the melting point of Si, placing a film which is evaporated more easily than such film and single-crystallizing a thin film around said film with the heating of a short period of time. CONSTITUTION:A poly-Si or thin film of amorphous Si, SiO2 thin film 7 (not liquified at the melting point of Si) and a poly-Si thin film 8 (evaporated more easily than SiO2) are provided on a quartz substrate 5, it is then irradiated with laser beam for a short period of time. When the Si thin film 6 is melted, heating is suspended. Heat of film 6 does not escape to the substrae 5, convection is not generated at the surface of substrate because of the heating during a short period of time, Si is evaporated from the poly-Si 8 getting evaporation heat, thereby cooling becomes effective and the film 6 is cooled quicker than the circumference. Accordingly, a single crystal region can be obtained around the region allowing existence of poly-Si 8. In the case of heating by laser beam, the SiO2 film in the thickness of 850Angstrom is effective. According to this structure, the SOI single crystal can be obtained at the desired region regardless of the underlayer structure. |
