| 摘要 |
<p>PURPOSE:To reduce channel currents on a writing remarkably by implanting ions of the same conduction type as a substrate to a channel section positioned under an insulating film, to which a floating gate electrode is formed, and previously increasing impurity concentration in the channel section when preparing a gate type semiconductor nonvolatile memory. CONSTITUTION:An impurity of a conduction type different from a semiconductor substrate 1 is diffused to the surface layer section of the substrate to form a drain region 3, and the whole surface containing the region 3 is coated thinly with an Si3N4 first insulating film 4 of comparatively high permittivity. A floating gate electrode 5 is placed on the film 4 while one part of its end section is made correspond to the region 3, but impurity ions of the same conduction type as the substrate are implanted to the surface under the film 4 corresponding to the electrode 5 at that time to previously form a channel region 9 in high concentration. The whole surface is coated with a second insulating film 6, a window is bored and an electrode for applying voltage VD is mounted to the region 3, and a control gate electrode 7 applying voltage VCG is set up on the film 6 corresponding to the electrode 5.</p> |
