| 摘要 |
PURPOSE:To maintain a large degree of freedom in order to optimize various transistors and to enhance a performance furthermore by a method wherein a gate insulating film of a transfer transistor is formed to be thicker than a gate insulating film of a transistor other than the transfer transistor. CONSTITUTION:Gate insulating films IG1, IG2 of a transistor in a memory cell part MC are formed to be thick as compared with the gate insulating film IG2 of a transistor in a part PC other than the memory cell. Accordingly, film thicknesses of the gate insulating film in the transfer transistor and the gate insulating film in the transistor in the part other than the memory cell can be decided independently of each other. Thereby, this device can be optimized so as to deal with various problems caused when a switching speed is enhanced, a short channel is eliminated or a life of a memory cell is shortened by a situation that the gate insulating film captures carriers; when these problems are solved, performance can be enhanced furthermore. |
