US Patent 11411097 Semiconductor device

Provided is a semiconductor device including a substrate, a plurality of memory cells, and at least one dummy gate structure. The substrate has a memory cell region and a dummy region. The memory cells are disposed on the substrate in the memory cell region. Each memory cell includes: adjacent two stack structures disposed on the substrate; two select gates respectively disposed outside the adjacent two stack structures; and an erase gate disposed between the adjacent two stack structures. The erase gate has a step between a topmost top surface and a lowermost top surface of the erase gate. The at least one dummy gate structure is disposed on the substrate in the dummy region.