Semiconductor device and a method of manufacturing the same

Abstract

A semiconductor device has a nonvolatile memory employing a split-gate type memory cell structure, using a nitride film as a charge storage layer. An n-type semiconductor region is formed in a main surface of a semiconductor substrate, and then, a memory gate electrode of a memory cell of a split gate type and a charge storage layer are formed over the semiconductor region. Subsequently, side walls are formed on side surfaces of the memory gate electrode, and a photoresist pattern is formed over the main surface of the semiconductor substrate. The photoresist pattern serves as an etching mask, and a part of the main surface of the semiconductor substrate is removed by etching to form a dent. In the region of the dent, the n-type semiconductor region is removed. Then, a p-type semiconductor region for forming a channel of an nMIS transistor for selecting a memory cell is formed.