Semicondudctor device

摘要

A semiconductor device includes a plurality of nonvolatile memory cells ( 1 ). Each of the nonvolatile memory cells comprises a MOS type first transistor section ( 3 ) used for information storage, and a MOS type second transistor section ( 4 ) which selects the first transistor section. The second transistor section has a bit line electrode ( 16 ) connected to a bit line, and a control gate electrode ( 18 ) connected to a control gate control line. The first transistor section has a source line electrode ( 10 ) connected to a source line, a memory gate electrode ( 14 ) connected to a memory gate control line, and a charge storage region ( 11 ) disposed directly below the memory gate electrode. A gate withstand voltage of the second transistor section is lower than that of the first transistor section. Assuming that the thickness of a gate insulating film of the second transistor section is defined as tc and the thickness of a gate insulating film of the first transistor section is defined as tm, they have a relationship of tc