| 摘要 |
PROBLEM TO BE SOLVED: To provide an LDD (lightly doped drain) semiconductor device which allows less drain currents to flow when in an off state, and which is capable of dealing with high voltage. SOLUTION: A polysilicon film 4a, a CVD oxide film 5a, and a resist pattern 6 serving as a gate electrode 7 are formed on a thermal oxidation film 3 (step 2). Subsequently, the CVD oxide film 5a is side etched to form a CVD oxide film 5b with a size smaller than the polysilicon film 4a (step 3). A high concentration impurity is injected, using the resist pattern 6 as a mask, to form a high concentration source-drain region 8 at a position where the source-drain region 8 does not overlap the polysilicon film 4a. Then, the resist pattern 6 is removed, and a low concentration impurity is injected, using the CVD oxide film 5b as a mask, to form a low concentration LDD region at a position where the LDD region overlaps the gate electrode 7 made of the polysilicon film 4a. COPYRIGHT: (C)2007,JPO&INPIT
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