| 摘要 |
PURPOSE:To enable to miniaturize a memory unit and to write and erase data by a method wherein the substrate face consisting of impurity diffusion layer region of reverse conductivity type to a semiconductor substrate is selectively oxidized to form a field insulating film and, in addition to it, another insulating film is formed on the impurity diffusion layer region. CONSTITUTION:An SiO2 film 74 is ormed by etching of SiO2 films 71, 72 after forming the impurity diffusion layer 73 of reverse conductivity type to a substrate 1. Then, silicon nitride film 75 is formed on the film 74 by vapor growth, and a channel stopper 76 is produced by ion implantation with patterning over a part which is to be an active region, and a thick field SiO2 film 77 is formed by selective oxidation. Next, etching of only part of the SiO2 film on a tunnel gate region which is encompassed by the field SiO2 film 77 results in exposure of diffusion layer 73b produced by doping of impurities on which the second SiO2 film 6 is formed for bi-directional tunnelling effect. |
