Hole and valence band electron tunneling in a P-channel Si nano-crystal memory

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 w ith low programming voltage. By comparing the characteristics between devic es with dots and devices without dots, we show that the holes tunnel into t he 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 dot s during programming. However, for large programming voltages, electron tun neling from the dot into the substrate becomes dominant. We also show that the programmed holes recombine with the electrons that tunnel from the subs trate during Erasing. Finally. the retention characteristics of programmed holes and electrons are compared.