| 摘要 |
PROBLEM TO BE SOLVED: To improve driving capability and breakdown voltage of a high-breakdown-voltage MOSFET. SOLUTION: A P-type second drain region 6 is formed in an N-type well region 4 formed in a P-type semiconductor substrate 2. A LOCOS oxide film 8 is formed on the second drain region 6, and a P-type third drain region 10 having a P-type impurity concentration higher than that of the P-type second drain region 6 is formed in a region underneath the LOCOS oxide film 8a. A gate oxide film 12 is formed on the surface of the N-type well region 4, extending continuously to the LOCOS oxide film 8a. A gate electrode 14 is formed on the gate oxide film 12, extending over the LOCOS oxide film 8a. A P-type first drain region 16 is formed in the surface vicinity of the P-type second drain region 6 keeping a space from the gate electrode 14. The P-type first drain region 16 has a P-type impurity concentration higher than those of the P-type second drain region 6 and the P-type third drain region 10. COPYRIGHT: (C)2007,JPO&INPIT
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