| 摘要 |
PURPOSE: To increase polysilicon grain size, uniformly oriented in a prescribed face orientation and to precisely control crystal grain positions by making crystal grain size of each layer in a prescribed planar region increase larger, as the layer goes upward. CONSTITUTION: A first-layer polycrystalline semiconductor film 2 composed of polycrystals is formed on a surface of an insulating substrate 1 (a). Next, by using an anisotropric etching solution, the first-layer polycrystalline semiconductor film 2 is etched selectively leaving a specific face orientation. Subsequently, by using a photomask, the specific regions are reserved, while other regions are etched this time by an etchant which is independent on crystal orientation. By this process, the continuity of the first-layer protrusions S1 constituted by a specified face orientation is formed on the surface of the first-layer polycrystalline semiconductor film 2 (b). Next, a second-layer amorphous semiconductor film 4a composed of amorphous silicon is deposited on the first-layer polycrystalline film 2 (c). By repeating this process several times, diameter of a single crystal 10 can be made as large as desired.
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