Semiconductor device and forming method thereof

Abstract

A semiconductor device and a forming method thereof are provided. The semiconductor device comprises a semiconductor substrate, a first shallow trench isolation structure which is disposed in the semiconductor substrate and of which the top surface is higher than the surface of the semiconductor substrate, a drift region which is disposed in the semiconductor substrate and surrounds the first shallow trench isolation structure and of which the depth is greater than the depth of the first shallow trench isolation structure, a first body region which is disposed in the semiconductor substrate on one side of the drift region and is of a doping type opposite to the doping type of the drift region, a first gate structure which is disposed on the semiconductor substrate and stretches across and covers part of the surfaces of the body region, the semiconductor substrate, the drift region and the first shallow trench isolation structure, a first drain region which is disposed in the drift region on one side of the first gate structure, and a first source region which is disposed in the first body region on the other side of the first gate structure. The gate-drain parasitic capacitance of the semiconductor device is reduced.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a semiconductor device 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 f...

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