| 摘要 |
PURPOSE:To obtain eacily the single crystal thin film capable of being flattened substantially on the upper face thereof according to the bridging epitaxy method by a method wherein transparant films are adhered on stacked films at least on the inner surface of concave parts to be used as reflection preventing films of a laser beam. CONSTITUTION:Thermal oxide films 2 are formed at the interval of 2mum on the surface of an Si substrate 1 according to normal photolithography technique. Then a polycrystalline silicon film 3 is adhered on the whole surface using CVD technique, and the continuously oscillating Ar laser is scanningly irradiated with the beam diameter of 70mum, energy of 7W, and at the speed of 20cm/s from the upper part thereof. As a result, the polycrystalline silicon film on the thermal oxide films 2 is molten, and grain size is enlarged, while the polycrystalline silicon film on the Si substrate is not molten, and bridging epitaxy is not generated. Then the SiO2 films 4 are stacked one upon another according to CVD technique only on the upper parts of the polycrystalline silicon films on the Si substrate using a proper mask pattern, and irradiation of the continuously oscillating Ar laser is performed from the upper part thereof in the inrradiating condition the same with the condition mentioned above. As a result, not only the polycrystalline silicon films on the SiO2 films, but the polycrystalline silicon films stacked on the Si substrate are also molten, liquid phase epitaxial growth is performed on the Si substrate, and at the same time, bridging epitaxy is generated, and the polycrystalline silicon films on the SiO2 films are converted completely into the single crystal films, and moreover the upper face thereof is flattened. |
