Hole and Valence Band Electron Tunneling in a P-Channel Si Nano-Crystal Memory

Abstract

In this work, the hole tunneling and the Valence band electron tunneling in a D-channel nanocrystal memory is studied for the first time. We show that the nano-crystal memory carl be applied to practical memory applications with low programming voltage. By comparing the characteristics between devices with dots and devices without dots, we show that the holes tunnel into the dots. The hole tunneling component and the electron tunneling component can be separated successfully by using a carrier separation technique. For small gate voltages. the holes from the inversion layer tunnel into the dots during programming. However, for large programming voltages, electron tunneling from the dot into the substrate becomes dominant. We also show that the programmed holes recombine with the electrons that tunnel from the substrate during Erasing. Finally. the retention characteristics of programmed holes and electrons are compared.