Patent ID: 6670666
Filing Date: 2003-12-30
Classification: H01L

Abstract:
A non-volatile semiconductor memory device having a source diffusion layer region formed continuously at a main surface of a semiconductor substrate, whereinthe main surface of said semiconductor substrate as said source diffusion layer region has, in a cross section parallel to a direction of extension of said source diffusion layer region, recesses and protrusions, formed by trench isolation method, continuously and alternately repeated; said source diffusion layer region includes a first source diffusion layer region formed, when said semiconductor substrate is viewed two-dimensionally, from an upper surface of each said protrusion to depth direction of said semiconductor substrate, and a second source diffusion layer region formed, when said semiconductor substrate is viewed two-dimensionally, from a bottom surface of said recess to the depth direction of said semiconductor substrate; depth of a bottom surface of said first source diffusion layer region from the upper surface of said protrusion is equal to or larger than depth of a bottom surface of each said recess from the upper surface of the protrusion; and depth of a shallowest portion in the depth direction of the first source diffusion layer region from the under surface of the protrusion is equal to or larger than a deepest portion of the recess in the depth direction from the upper surface of the protrusion.