LDMOS transistor and formation method thereof

Abstract

A LDMOS transistor and a formation method thereof are provided; the method comprises the following steps: providing a semiconductor substrate, and forming a shallow trench isolation structure in the semiconductor substrate; forming a drift region in the semiconductor substrate, wherein the drift region encloses the shallow trench isolation structure; forming a body region in the semiconductor substrate on the drift region side; forming a gate structure crossing and covering partial the body region, the drift region and the shallow trench isolation structure; forming a drain region in the driftregion on the gate structure side; forming a source region in the body region on the other side of the gate structure; forming a first shallow doping region in the drain region on the gate structureside and in the drift region on the gate structure bottom, wherein the first shallow doping region doping type is same with the drain region doping type, and the first shallow doping region depth is smaller than the drain region depth and drift region depth. The method can improve the LDMOS transistor working current.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to an LDMOS transistor and a forming method thereof. Background technique [0002] The power field effect transistor mainly includes two types: a vertical double-diffused field effect transistor (VDMOS, Vertical Double-Diffused MOSFET) and a lateral double-diffused field effect transistor (LDMOS, Lateral Double-Diffused MOSFET). Among them, compared with the vertical double diffused field effect transistor (VDMOS), the lateral double diffused field effect transistor (LDMOS) has many advantages, for example, the latter has better thermal stability and frequency stability, higher gain and durability stability, lower feedback capacitance and thermal resistance, as well as constant input impedance and simpler bias current circuitry. [0003] In the prior art, a conventional N-type lateral double-diffused field effect transistor (LDMOS transistor) structure is as follows figu...

AI Technical Summary

Problems solved by technology

[0004] However, the performance of the existing lateral double diffused field effect transistor (LDMOS transistor) still needs to be improved.

Images