| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of a conventional semiconductor device that electric field relaxation cannot be achieved easily in a drain region when the drain region is formed of a DDD structure by thinning a gate oxide film. SOLUTION: In a method for manufacturing a semiconductor device, a thin gate oxide film 12 is formed on the upper surface of a P type diffusion layer 5. A gate electrode 9 is formed on the upper surface of the gate oxide film 12. N type diffusion layers 7 and 8 are formed on the P type diffusion layer 5, and the N type diffusion layer 8 is used as a drain region. The N type diffusion layer 8 is diffused in aγ-shape at least under a gate electrode 9. By such a structure, the N type diffusion layer 8 spreads in the vicinity of the surface of an epitaxial layer 4 and becomes a low concentration region. Consequently, electric fields from the gate electrode and the electric field between a source and a drain can be relaxed. COPYRIGHT: (C)2007,JPO&INPIT
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