In-depth analysis of 3D Silicon nanowire SONOS memory characteristics by TCAD simulations

In this work, we present a detailed investigation of the electrical characteristics of 3D Gate-All-Around (GAA) Silicon nanowire (down to 6nm-diameter) SONOS memories compared to standard planar SONOS devices. In particular, by means of TCAD simulations, the write, erase and retention characteristics under uniform FN stress are explained and the main geometrical and electrostatic effects of 3D cylindrical devices are put in evidence. The physical mechanisms dominating the 3D devices performance and reliability are identified. In particular, the great influence of band-to-band phenomenon in the erase characteristics is underlined.