| 摘要 |
PURPOSE:To contrive to stabilize electric characteristics by a method wherein the junction region between a P-layer and an N-layer is provided with a single crystal layer, in a device using an amorphous or polycrystalline semiconductor. CONSTITUTION:A poly Si layer is provided on an insulation substrate or an insulation layer 1, and regions 4 and 5 are turned into the state of single crystal by the liquid phase growth with laser beams along the region 7 forming the P-N junction. A region 6 represents a grain boundary. Next, the P-N junction is formed by the diffusion of a P type impurity to regions 2 and 4 and an N type impurity to regions 3 and 5. Single crystallization in a large area with laser beams is difficult; however, the characteristic of the P-N junction is determined by single crystal Si layers 4 and 5, not depending on poly Si layers 2 and 3. Therefore, a stable breakdown voltage and a low reverse bias current can be obtained, and accordingly a protecting circuit excellent in characteristics can be formed. |
