Lateral double diffused field effect transistor and method of forming the same

Abstract

A lateral double diffused field effect transistor and its forming method. The lateral double diffused field effect transistor comprises: a semiconductor substrate doped with impurity ions of a first conductivity type; a first shallow trench located in the semiconductor substrate Trench isolation structure; a drift region located in the semiconductor substrate, the drift region surrounds the first shallow trench isolation structure, the drift region is doped with impurity ions of a second conductivity type, the second conductivity type is opposite to the first conductivity type ; An inversion doped region located in the drift region, the depth of the inversion doped region is less than the depth of the drift region, and the inversion doped region is doped with impurity ions of the first conductivity type; The body region in the semiconductor substrate is doped with impurity ions of the first conductivity type; a gate structure is formed on the semiconductor substrate, one end of the gate structure extends above the body region, and the other end extends to the first above the shallow trench isolation structure. The gate-to-drain parasitic capacitance of the lateral double-diffused field effect transistor is reduced.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a lateral double-diffusion field effect 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-diffusion field effect transistor structure is as ...

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Problems solved by technology

[0004] However, the performance of the existing lateral double diffused field effect transistors still needs to be improved

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