| 摘要 |
<p>A MISFET constituting a nonvolatile memory, composed of a gate electrode formed on a gate insulating film, an n+ semiconductor region (drain) whose one end is extended below the gate electrode, an n+ semiconductor region (high concentration source) formed so as to be at an offset position relative to the gate electrode, and an n- semiconductor region (low concentration source) whose one end is extended below the gate electrode, wherein the portion of the gate insulating film on the drain side is a silicon oxide film, and the portion of the gate insulating film on the source side is a three-layer insulating structure including a silicon oxide film, a silicon nitride film and a silicon oxide film. Writing in the nonvolatile memory cell is performed by making the potential of the drain higher than the potential of the source and injecting hot electrons generated in the end part of the low concentration source into the silicon nitride film constituting part of the gate insulating film.</p> |
