Being the semiconductor device where the semiconductor device

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device and a method of manufacturing the same including an LDMOS (Laterally Diffused MOS) having a plurality of device withstand voltage zones and good on-resistance on the same wafer or product as compared with a conventional manufacturing method.SOLUTION: The plurality of device withstand voltages and good on-resistance are achieved on the same wafer by separately optimizing thicknesses of a first electric field relaxing oxide film 24, a second electric field relaxing oxide film 25, and an element separation LOCOS (Local Oxidation of Silicon) oxide film 17.