| 摘要 |
PURPOSE:To contrive single crystallization over large area by performing recrystallization with scanning polycrystalline or amorphous semiconductor thin film on an insulating film by laser beam showing multipeak distribution thereby giving precedence to crystal grains at specified positions as nuclei of recrystallization. CONSTITUTION:A silicon oxide film 20 is formed on surface of a single crystal silicon substrate 10 by thermal oxidation or the like and next, a polycrystalline silicon film 30 is formed over the whole surface. Meanwhile, laser beam 40 having Gaussian distribution of intensity permeates through a quartz birefringence plate 50 once and separates into two beams. When the polycrystalline silicon film 30 is scanned by multipeak-type laser beam 41 in the scanning direction 1, it is once fused and then recrystallized. The direction 70 in which the recrystallization proceeds is determined according to shape of the laser beam which gathers toward the center in end parts 61 and expands toward the end parts in a central part 62. Accordingly, it is impossible to contrive single crystallization over large area in the end parts, however that is possible in the central parts 62 as crystal grains present at the central positions of twin-peak type distribution of intensity become nuclei of recrystallization. |
