Semiconductor device and a method of manufacturing the same

摘要

In a technique to improve the high-frequency power gain of an LDMOS, the distance from the surface of a passivation film covering electrode pads to the rear surface of a silicon substrate is set into 200 mum or less, or a trench of 2 mum or more in thickness, in which an insulating film or a conductor is embedded, is formed between a region where a p type impurity is diffused, when a p⁺ type source penetrating layer is formed, and the channel region of a third LDMOS, so as to extend from the front surface of a semiconductor layer toward a silicon substrate. This trench restrains the p⁺ type source penetrating layer from spreading to the channel region, thereby lowering the inductance or the resistance of the source and improving the high-frequency power gain.