Non-volatile semiconductor memory device having a floating gate inside a grove

摘要

A semiconductor well region has a groove into which a block- shaped floating gate is formed. The block-shaped floating gate has a bottom surface facing a bottom surface of the semiconductor well region served as a first channel region, a first side surface facing one of side surfaces of the semiconductor well region served as a second channel region, a second side surface facing the other of side surfaces of the semiconductor well region served as a third channel region, thereby a channel width is trebled.