| 摘要 |
PURPOSE:To obtain a single crystal with large grains when polycrystalline silicon is single crystallized by a method wherein a laser beam emitted from a single laser beam source is caused to optically branch off into two and an annealing process is conducted by making the two laser beams adjacent to each other. CONSTITUTION:This arrangement comprises a laser beam source 1, a total reflection mirror 2, a half reflection mirror 3, a total reflection mirror 4, a two- dimensional laser beam pattern LB' and the distribution of three-dimensional laser beam strength BS'. Since a semiconductor wafer can be annealed with laser beams having small energy density in the central portion and large energy density in the peripheral portion, single crystallization proceeds outwardly from the central portion when a polycrystalline silicon is single crystallized, so that a single crystal with large grains can be obtained. |
