| 摘要 |
<p>PURPOSE:To make miniaturization of ROM possible by performing ion- inplantation into a non-selective region for inverse doping while masking a MOS transistor region of a second gate. CONSTITUTION:An N<-> implantation region 10 is formed by previous ion implantation including the part of a second gate region on a semiconductor substrate 1, while a part of this second region part is inversely doped according to a program cord of a ROM. Accordingly, control of threshold value voltage becomes possible in a self-alignment manner with respect to a first gate electrode. Thereby, miniaturization of the second gate electrode becomes possible so that the ROM of high density and a large capacity can be easily realized.</p> |
