| 摘要 |
PURPOSE:To prevent the deterioration of characteristics due to the effect of a series resistor by forming a semiconductor region section having intermediate concentration between a semiconductor region section having low concentration and a semiconductor region section having high concentration in LDD structure. CONSTITUTION:A large number of active regions are partitioned to the surface of a semiconductor substrate 1 consisting of P-type silicon, etc. by isolation regions 2 composed of selective oxide films, and a MOSFET3 is shaped in the active regions. The sections (third semiconductor region sections) 63, 73 of source and drain each region 6, 7 corresponding to several contact hole 11 are formed in a high-concentration N<++> type in order to take an excellent ohmic contact. However, N<-> type low-concentration first semiconductor region sections 61, 71 and N<+> type intermediate-concentration second semiconductor region sections 62, 72 are shaped at end sections on the channel side. These first, second and third respective semiconductor region section is formed by utilizing ion implantation using a gate electrode 5 and/or side walls 8 as masks. |
