Semiconductor device and manufacturing method thereof

摘要

An active layer is formed by using a crystalline silicon film that has been crystallized by utilizing a metal element for accelerating crystallization. A heat treatment is performed in an atmosphere containing a halogen element to remove the metal element by gettering. As a result, the active layer becomes a crystal structural body that is a collection of a plurality of needle-like or columnar crystals. A semiconductor device constructed by using this crystal structural body is given much superior performance.