| 摘要 |
PURPOSE:To provide a semiconductor device with excellent P<+> ohmic characteristics by a method wherein, within the manufacturing process of complementary MOS semiconductor integrated circuit with multiple layered wiring structure, ROM is decided after making contact holes to shorten the process term after ROM is decided further increasing the boron concentration in P<+> contact regions. CONSTITUTION:Specified resist patterns 13 are formed on depression transistor regions and polysilicon respectively on P<+> diffused layers and N<+> diffused layers. Later PSG film and said oxide film only in the contact regions on P<+> diffused layers are entirely removed for etching process. First, the contact regions on P<+> diffused layer are implanted with boron at 10KeV of energy and 10<13>-10<14>cm<-2> of implantation level to increase the boron concentration only thereon. Second, after removing the needless resist 13, source.drain gate regions are opened to form the other resist patterns 14. Finally the resist patterns 14 are implanted with phosphorus at 250-350KeV, 1X10<13>-1X10<14>cm<-2> to make depression transistor mode. |
