| 摘要 |
PURPOSE:To remove the variation of threshold voltage by bringing a surface section to high impurity concentration, and to reduce junction capacitance by bringing a section deeper than the surface section to low impurity concentration by controlling impurity concentration through the diffusion of at least two kinds of impurities having different diffusion constants in an MISFET. CONSTITUTION:A high concentration region 18 having aimed depth can be shaped to a channel section in excellent reproducibility because phosphorus 21 and arsenic are implanted while using a mask 19 determining an N type well 2 in common and the well 2 and the high concentration region 18 are formed by utilizing the difference of the extension diffusion constants. Since the high concentration region 18 and a channel stopper 13 can be shaped substantially through the ion implantation of one process only by selecting the kinds of implantation ions without adding masks in case of injection at all, a normal manufacturing process need not be varied or processes need not be added, and working property is improved. |
