| 摘要 |
PURPOSE:To miniaturize an impurity region, reduce the contact resistance value and hence to improve integration degree by a method wherein impurity regions are formed in a semiconductor substrate with impurities having the same conductive type but different diffusion coefficients. CONSTITUTION:Phosphorus 6 is ion-implanted with a regist film 5 used as a mask. Then, arsenic 8 is ion-implanted with the regist film 5 used as a mask again to form impurity regions 7' including the phosphorus 6 and arsenic 8 in a P-well layer 4. The arsenic 8 having a relatively small diffusion coefficient functions such that both siffusion width and diffusion depth of each impurity region 7' are not undesirously enlarged through heat processing. Thereafter, a conductive layer is formed entirely over the impurity regions 7, 10, oxide film 13a and an oxide film 11. Then, the conductive layer under goes a predetermined patterning to form a leading out wiring layer 14 connected to an N-channel MOSFET formed with the impurity regions 7, 7 in the P-well layer 4 and to a P-channel MOSFET formed with the impurity region 10 formed in a semiconductor substrate 1, as well as gate electrodes 15a, 15b for those channels, thus providing a semiconductor device 20. |
