| 摘要 |
<p>A semiconductor nonvolatile memory device to store multinary data comprises a memory cell having source and drain regions (S, D) formed in the surface of a semiconductor substrate, a gate insulating film and a control gate (CG) formed on a channel region (CH) between the source and drain regions, and a nonconductive trap gate in the gate insulating film. A recess (4) extending from a portion that is near the drain region and in the channel region to the drain region is formed in the surface of the semiconductor substrate. By thus providing such a recess (4) near the drain region and in the channel region, the trap gate is located in the direction of the channel current flowing from the source region (S) to the drain region (D), and charges travelling through the channel region (CH) are efficiently injected into the trap gate over the recess. Therefore, without applying a high voltage to the control gate (CG), hot charges can be injected into the trap gate.</p> |
