| 摘要 |
PROBLEM TO BE SOLVED: To enable high-speed writing, erasing and reading by reducing a thickness of a second gate insulating film of a MISFET constituting a memory cell in a non-volatile memory. SOLUTION: A second gate insulating film 7 of a MISFET (Qm) constituting a memory cell in a non-volatile memory is constituted of four layers of a lower silicon oxide film 7a, lower silicon nitride film (high dielectric film) 7b, upper silicon oxide film 7c and upper silicon nitride film (barrier film) 7d. Thus, impurities in a control gate 8 are prevented from diffusing in the upper silicon oxide film 7c. |
