| 摘要 |
PURPOSE:To reduce a current until next breakdown occurs by forming a plurality of one conductive type regions in high impurity density, thereby increasing the operating resistance after the breakdown. CONSTITUTION:When a diffusion is achieved to the prescribed depth x through a plurality of diffusion windows of a semiconductor substrate 1, since an interval among the respective windows is formed smaller than 2x, the respective diffused regions are connected due to lateral diffusion, thereby forming P type regions 2a-2c of high impurity density. Then, a P type region 3 is formed to include the regions 2a-2c therein. A high density N type region 4 is formed by covering the regions 2a-2c in the region 3. Anode and cathode electrodes are respectively covered on the regions 3 and 4. According to this, the areas of the high density regions 9a-9c directly under the diffusion window become small, and the area of the relatively low density region of lateral diffusion can be reduced. Accordingly, the resistance after the breakdown becomes large, and the current until the next breakdown occurs becomes considerably small. |
