Patent ID: 7847365

Claim:
A P-type metal oxide semiconductor field effect transistor (MOSFET), comprising: a P-type substrate; a first N-type diffusion region having N conductivity-type ions, forming a first N-well in the P-type substrate; a first P-type diffusion region having P conductivity-type ions, forming a first P-type region in the first N-well; a first drain diffusion region having P+ conductivity-type ions, forming a first drain region in the first P-type diffusion region; a first source diffusion region having P+ conductivity-type ions, forming a first source region, wherein a first channel is formed between the first source region and the first drain region; a first contact diffusion region having N+ conductivity-type ions, forming a first contact region, wherein the first N-type diffusion region surrounds the first source region and the first contact region; a plurality of separated P-type diffusion regions having P conductivity-type ions, forming a plurality of separated P-type regions in the P-type substrate to provide an isolation effect; a first thin gate oxide layer and a first thick field oxide layer, formed on the P-type substrate; a first gate, disposed on the first thin gate oxide layer, for controlling an amount of current in the first channel; a silicon oxide insulating layer, covering the first gate and the first thick field oxide layer; a first drain metal contact, having a first metal electrode connected with the first drain diffusion region; and a first source metal contact, having a second metal electrode connected to the first contact diffusion region and the first source diffusion region.