SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To solve the problem wherein the withstand voltage characteristics (= punch-through characteristics) between the source region and the drain region is deteriorated and short-channel effect is reduced when, in a process for manufacturing a MOS transistor, an impurity diffused layer is formed at a position in the source region and the drain region, and then heat treatment of high temperature (for example: about 1,000°C) is performed, because the region of each impurity diffused layer is made to widen. SOLUTION: Previously, a silicon substrate 100 is provided with silicon oxide films 107 and 108. Then, on both sides of polycrystalline silicon films 117 (= gate electrode layer), N-type impurity diffused layers 118a and 118b and P-type impurity diffused layers 119a and 119b (LDD regions) are formed. Even if heat high-temperature heat treatment is subsequently performed under this condition, spread of each impurity diffused layer constituting the LDD region is restrained by the silicon oxide films 107 and 108. COPYRIGHT: (C)2004,JPO