US Patent 7804120 Non-volatile semiconductor memory devices

A non-volatile memory device includes a tunneling insulating layer on a semiconductor substrate, a charge storage layer, a blocking insulating layer, and a gate electrode. The charge storage layer is on the tunnel insulating layer and has a smaller band gap than the tunnel insulating layer and has a greater band gap than the semiconductor substrate. The blocking insulating layer is on the charge storage layer and has a greater band gap than the charge storage layer and has a smaller band gap than the tunnel insulating layer. The gate electrode is on the blocking insulating layer.