Transverse diffusion semiconductor device and preparation method thereof

Abstract

The invention relates to a transverse diffusion semiconductor device and a preparation method thereof. The method comprises the steps of providing a semiconductor substrate, and forming a well region and a drift region in the semiconductor substrate; forming stepped gate dielectric layers on the semiconductor substrate, wherein the gate dielectric layer positioned above a channel region is thinner; forming a gate structure on each of the stepped gate dielectric layers, and executing source and drain injection, so as to form source and drain regions on both sides of each gate structure. According to the semiconductor device, the stepped gate dielectric layers with different heights are formed on the semiconductor substrate, so as to further form the gate structures, and the method is used for increasing the breakdown voltage between drain and source (BVDS) of the device, so that the performance of the device is further improved.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular, the invention relates to a lateral diffusion semiconductor device and a preparation method thereof. Background technique [0002] With the rapid development of the semiconductor industry, PIC (Power Integrated Circuit, power integrated circuit) is continuously used in many fields, such as motor control, flat panel display drive control, computer peripheral drive control, etc., the PIC circuit used Among power devices, DMOS (Double Diffused MOSFET, Double Diffused Metal Oxide Semiconductor Field Effect Transistor) has high operating voltage, simple process, and is easy to be compatible with low-voltage CMOS (Complementary Metal Oxide Semiconductor, Complementary Metal Oxide Semiconductor) circuits in terms of process, etc. characteristics have received widespread attention. [0003] There are two main types of DMOS: vertical double-diffused MOSFET (VDMOS) and lateral double-diffused M...

AI Technical Summary

Problems solved by technology

However, the LDMOS of the structure still has a source-drain breakdown voltage (Breakdown Voltage between Drain and Source, BVDS) is still low, which cannot meet the needs of further development of the device, and the source and drain are easily broken down, causing device damage

[0007] Therefore, although LDMOS has many characteristics that conventional transistors do not have, the development and application of said LDMOS are largely limited due to its low breakdown voltage, so it is necessary to improve the structure of existing LDMOS to Further improve the source-drain breakdown voltage of LDMOS and further improve the performance of LDMOS transistors

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