| 摘要 |
PURPOSE:To improve avalanche breakdown strength by preventing heat generation by operation of a parasitic transistor and heat generation by a device inside resistance element by bringing a substrate electrode into contact with a substrate exposed part at a counter drain electrode side of a source electrode and by providing a current path of a low resistance to the other side of a semiconductor substrate. CONSTITUTION:An N-well 2, an n-drain region 8 and a DP well 9 are formed in a surface layer of a p-type FZ method silicon substrate 1, and a pair of n<+>-source regions 5, a first p-base region 3 and a second p-base region 4 are formed inside the N-well 2. Furthermore, a gate electrode 7 is provided to a surface of the n<+>-source region 5 and the p-base region 3 interposing a gate oxide film 6. An electrode 14 is formed in a rear of the p-substrate 1 and brought into ohmic contact with a substrate and an electric potential of the rear electrode 14 is made GND. A current path 25 wherein an avalanche current flows to a substrate rear is formed by the rear electrode 14. A resistance R3 of the current path 25 is smaller than R1 and R2. |
