Contactless nonvolatile memory device and method of forming the same

Abstract

A method of forming a contactless nonvolatile memory device includes preparing a semiconductor substrate including a cell array region, forming a plurality of mask patterns being parallel to each other on the semiconductor substrate in the cell array region, etching the semiconductor substrate using the mask patterns as an etch mask to form a plurality of recess regions, forming a gate insulating layer on sidewalls and bottoms of the recess regions, forming a floating gate layer on an upper surface of the semiconductor substrate to fill the recess regions, planarizing the floating gate layer to expose upper surfaces of the mask patterns and to form floating gate patterns in the recess regions, forming buried impurity diffusion regions in the semiconductor substrate under the mask patterns, forming an intergate dielectric layer, forming a control gate layer, and patterning the control gate layer, the intergate dielectric layer and the floating gate pattern to form a plurality of parallel word lines crossing the mask patterns, floating gates between the word lines and the recess regions, and an intergate dielectric pattern between the floating gates and the word lines, and to expose the recess regions and the mask patterns between word lines.