Patent ID: 7671404
Filing Date: 2010-03-02
Classification: H01L

Abstract:
1. A non-volatile semiconductor memory device, comprising: a semiconductor substrate; first and second semiconductor regions formed in the semiconductor substrate; a first region between the first semiconductor region and the second semiconductor region; a charge accumulation region formed above the first region via a first insulator; and wherein the charge density of an impurity on the side close to the second semiconductor region in the first region is higher than that on the side close to the first semiconductor region in the first region, wherein the charge accumulation region is erased by injecting holes, and wherein the holes are injected, from a part in the first region on the side closer to the second semiconductor region than the first semiconductor region, to the charge accumulation region, wherein the first region comprises a second region located on the side close to the first semiconductor region and a third region located on the side close to the second semiconductor region, wherein the charge accumulation region is formed above the third region and a first electrode is formed above the second region via an insulator, and wherein the charge density of an impurity in the second region is higher than that in the third region.