Patent ID: 6670243
Filing Date: 2003-12-30
Classification: H01L

Abstract:
A method of manufacturing a semiconductor memory device on a semiconductor substrate, comprising the steps of:depositing a first oxide film on the semiconductor substrate; forming a field oxide film in the first oxide film such that a plurality of grooves extend in a predetermined direction and exposes the semiconductor substrate, the field oxide film having a single forward taper shape; depositing a second oxide film on the exposed surface of the semiconductor substrate; and forming a floating gate to a reverse taper shape between the field oxide film on the second oxide film, wherein a first sidewall angle is less than 90 degrees measured with respect to a horizontal line drawn between bottom points of the forward taper in the forward taper shape while a second sidewall angle is more than 90 degrees measured with respect to a horizontal line drawn between bottom points of the reverse taper in the reverse taper shape.