Nonvolatile semiconductor memory device and manufacturing method thereof

摘要

In a channel region between the source/drain diffusion layers, impurities of the same conductivity type as the well are doped in an area apart from the diffusion regions. By using as a mask the gate formed in advance, tilted ion implantation in opposite directions is performed to form the diffusion layers and heavily impurity doped region of the same conductivity type as the well in a self-alignment manner relative to the gate.