Semiconductor device and a manufacturing method thereof

Abstract

The reliability of a semiconductor device having a nonvolatile memory is improved. The memory cell of the nonvolatile memory is of a split gate type, and has first and second n type semiconductor regions in a semiconductor substrate, a control electrode formed over the substrate between the semiconductor regions via a first insulation film, and a memory gate electrode formed over the substrate between the semiconductor regions via a second insulation film having a charge accumulation part. The SSI method is used for write to the memory cell. During the read operation of the memory cell, the first and second semiconductor regions function as source and drain regions, respectively. The first width of the first sidewall spacer formed adjacent to the side surface of the memory gate electrode is larger than the second width of the second sidewall spacer formed adjacent to the side surface of the control gate electrode.