| 摘要 |
PROBLEM TO BE SOLVED: To obtain a semiconductor device of high breakdown voltage independent of the number of pulses. SOLUTION: A P-type anode layer 12 and a P--type RESURF layer 14 are formed on the surface of an N-type semiconductor substrate 10. Impurity ions are additionally implanted into the surface of the RESURF layer 14, which is lessened in impurity concentration due to the formation of an oxide film for the formation of an additional layer 21. By this setup, the surface of the RESURF layer 14 is enhanced in impurity concentration so as to become equal to those of the other parts of the RESURF layer 14, and a semiconductor device of high breakdown voltage independent of the number of pulses can be obtained.
|
