LDMOS device and manufacturing method thereof

Abstract

The invention provides an LDMOS device and a manufacturing method thereof. The device comprises: a substrate, a drain electrode, a source electrode, a gate electrode, and a drift region. The drift region includes a first drift region and a second drift region under the first drift region, wherein the width of the second drift region is smaller than the width of the first drift region. Compared with the prior art, under the condition of the same doping concentration, depth of an undepleted region can be effectively reduced, thereby increasing area of a depletion region, so that breakdown voltage of the LDMOS device can be improved. Therefore, in the case of ensuring the same withstand voltage as in the prior art, performance of the LDMOS device is improved by increasing the doping concentration of the drift region and reducing forward conduction resistance of the drift region. The LDMOS device effectively solves a contradiction problem of improving breakdown voltage and reducing forwardconduction resistance of a LDMOS device in the prior art.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, in particular to a lateral diffusion metal oxide semiconductor device and a preparation method thereof. Background technique [0002] In power integrated circuits such as BCD (bipolar transistor-complementary metal-oxide transistor-double-diffused metal-oxide transistor), a double-diffused metal-oxide transistor (Double-diffused Metal-Oxide-Silicon, DMOS) is usually included. DMOS specifically includes vertical double-diffused metal oxide transistors (referred to as "vertical transistors", namely Vertical Double-diffused Metal Oxide Semiconductor, referred to as VDMOS) and lateral double-diffused metal oxide transistors (referred to as "lateral transistors", namely Laterally Diffused Metal Oxide Semiconductor). , referred to as LDMOS). Due to its high operating voltage and simple process, LDMOS is easy to be compatible with devices such as complementary metal oxide transistors (CMOS) and ...

AI Technical Summary

Problems solved by technology

In LDMOS devices, the drift region used to bear the withstand voltage needs to be doped with a low concentration, but on the other hand, in order to reduce the on-resistance of the LDMOS device in forward conduction, the drift region as a current channel is required to have a high doping concentration. , which creates a contradiction between on-resistance and breakdown voltage

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