Patent ID: 6677203
Filing Date: 2004-01-13
Classification: H01L

Abstract:
A method for fabricating a semiconductor memory device, comprising the steps of:a) forming a plurality of isolations on a semiconductor substrate, thereby defining a plurality of active regions, which have been isolated from each other by the isolations, on the semiconductor substrate; b) forming a first insulating film and a first conductive film in this order over the semiconductor substrate and then selectively etching the first conductive film, thereby forming a control gate electrode out of the first conductive film so that the control gate electrode crosses all of the isolations and all of the active regions; c) forming a second insulating film and a second conductive film in this order over the semiconductor substrate as well as over the isolations and the control gate electrode and then selectively etching parts of the second conductive film, thereby forming floating gate electrodes out of the second conductive film for the active regions so that the floating gate electrodes cover a side face of the control gate electrode; and d) implanting ions into the semiconductor substrate using the control gate electrode and the floating gate electrodes as a mask, thereby defining source and drain regions in each said active region, wherein the step c) includes: forming and selectively etching the second conductive film to form a sidewall-shaped conductive film out of the second conductive film on the side face of the control gate electrode; removing parts of the sidewall-shaped conductive film and parts of the second conductive film from over the isolations, thereby forming the floating gate electrodes on the side face of the control gate electrode as islands out of the sidewall-shaped conductive film which are separated from each other on the isolations; and removing remaining parts of the second conductive film from upper and another side faces of the control gate electrode.