| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor memory device and its manufacturing method by which data-retention characteristics of a memory cell can be improved and fast turn-around in a peripheral circuitry can be achieved. <P>SOLUTION: A silicon oxide film on a semiconductor substrate 1 in a memory cell array region becomes thick by making a side wall film of a gate electrode 5 thick in the same region. Also, since the bird's beak in the lower part of the side wall is increased and the electric field between this part and source/drain diffusion layers 13 and 15 is reduced, the GIDL current is reduced, and the data-retention characteristics are improved. The silicon oxide film 4 on the semiconductor substrate 1 in a peripheral circuit region becomes thin by making the gate side wall thin in this region. Source/drain impurities can be ion implanted with low acceleration and the source/drain structure can be shallowly bonded. In this way, the short-channel effect of a transistor is suppressed and fast turn-around can be achieved. <P>COPYRIGHT: (C)2004,JPO |
