| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for forming a polycrystalline semiconductor film which allows an operation at a high speed with less fluctuations in characteristic and can manufacture a small TFT. SOLUTION: The method includes a step of scanning an irradiation zone while irradiating an amorphous silicon film formed in a island or strip shape with a continuous wave laser to convert the amorphous silicon film to a polysilicon film. When the width of a rectangle inscribed by the amorphous silicon film is not larger than 30 μm, the tip of the pattern has such a shape that satisfies a condition of one among (1) a projected shape, (2) a recessed shape of straight line having three angle parts of which the both-side parts form 45 degrees or more, (3) a recessed and curved shape at its tip, and (4) a shape having a width of 25 μm or less. |
