| 摘要 |
PURPOSE:To reduce the drain capacity of a semiconductor device by controlling a P type silicon substrate, an N-well, the surface of the substrate, P type and N type impurity layers to the specific impurity densities, and forming the N-well, and P type and N type impurity layers to the specific depths. CONSTITUTION:5X10<14>cm<-3> or lower of impurity density is used as a P type silicon substrate 201, and an N-well 202 is formed in depth of 2-10mum, and 1- 10X10<14>cm<-3> of impurity density. An element separation between MOS transistors is performed in a thermally oxidized film 203, and a channel stopper 204 is formed by P type diffused layer. Phosphorus ions are implanted by 1-5X 10<12>cm<-2> in the N-well region, boron ions are implanted to the P type substrate N-channel region, heat treated, and an N type diffused layer 206 and a P type diffused layer 207 are formed to become 0.5-1.5mum of depth, 1-3X10<16>cm<-3> of substrate surface density N-well region and N type substrate regions 1-6X 10<13>cm<-3>. A source and drain diffused layer 208 and a drain diffused layer 205 are formed by implanting ions to the gate electrode 210 of polycrystalline silicon, opening, and the forming wirings 209, thereby forming a passivation film 211. |
