Non-volatile semiconductor memory element and method of manufacturing the same, and semiconductor integrated circuit device including the non-volatile semiconductor memory element

Abstract

A non-volatile semiconductor memory element includes: a semiconductor region of a first conductivity type formed in a plate-like form on a semiconductor substrate; a first insulating film formed on a first side face of the semiconductor region; a first charge accumulating layer formed on a face of the first insulating film opposite from the semiconductor region; a second insulating film formed on a second side face of the semiconductor region, and has a different equivalent oxide thickness from the first insulating film; a second charge accumulating layer formed on a face of the second insulating film opposite from the semiconductor region; a third insulating film provided so as to cover the first and second charge accumulating layers; a control gate electrode provided so as to cover the third insulating film; a channel region formed in a portion of the semiconductor region covered with the control gate electrode; and source/drain regions of a second conductivity type formed in portions of the semiconductor region on both sides of the channel region.