Semiconductor nonvolatile memory, method of recording data in the semiconductor nonvolatile memory and method of reading data from the semiconductor nonvolatile memory

摘要

A memory cell structure and control of the memory operation are simplified, and the cost of production is decreased, by way of a semiconductor nonvolatile memory having a transistor including a gate electrode provided on a p-type semiconductor substrate via a gate insulating film, and a source region and a drain region, which are a pair of n-type impurity diffusion regions in the surface layer region of the semiconductor substrate at positions sandwiching the gate electrodes therebetween. A first resistance-varying portion and a second resistance-varying portion are sandwiched by the source region, drain region and channel-forming region. The n-type impurity concentration in the resistance-varying portions is lower than in the source and drain regions.