HIGH VOLTAGE LDMOS DEVICE

A high voltage lateral double diffused metal-oxide-semiconductor field effect transistor (LDMOS) comprises a substrate; an epitaxy layer on the substrate; a drift region on the epitaxy layer; and a drain region and a source region at two ends. At least one pair of n-type and p-type semiconductor regions is arranged alternately above the interface of the substrate and the epitaxy layer and firmly attached to a lower surface of the drifting region; the n-type and p-type semiconductor regions are firmly closed to each other and arranged to form a lateral PN junction; and the p-type semiconductor region and the drifting region form a vertical PN junction. The n-type and p-type semiconductor regions are also totally called "a reduced surface field (RESURF) layer in body", and the LDMOS device with a RESURF layer in body effectively solves conflict between raising reverse withstand voltage and reducing forward on-resistance of the current LDMOS devices.