LDMOS device and forming method thereof

Abstract

The invention discloses an LDMOS device and a forming method thereof. The method comprises the following steps: forming a field oxide layer on the surface of a deep well region, wherein the field oxide layer comprises a field oxide region and a beak region located at one end of the field oxide region in a first direction, the beak region is located on the surface of a first diffusion region, a part of the field oxide region is located on the surface of a second diffusion region, the field oxide layer has a third size in the first direction, the proportion range of the first distance to the third size is smaller than or equal to 30%, and the proportion range of the second distance to the third size is 20-80%; after the field oxide layer is formed, forming a body region is formed in the first doped region, wherein the body region has a first conductive type; and forming a grid electrode on the surface of a part of the field oxide layer, and enabling the grid electrode to further extend to the surface of a part of the body region. Different target breakdown voltage performance can be achieved by selecting different first distances and second distances.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to an LDMOS device and a forming method thereof. Background technique [0002] LDMOS devices (Lateral Double-Diffused Metal Oxide Semiconductor Field Effect Transistor, Lateral Double-Diffused Metal Oxide Semiconductor Field Effect Transistor) in high-voltage power devices have good process compatibility with CMOS devices due to the characteristics of current flowing laterally on the device surface. At the same time, compared with traditional power devices, LDMOS devices are widely used because of their good characteristics of high breakdown voltage and low on-resistance. [0003] In LDMOS devices, off-state breakdown voltage (Off-BV) and on-state breakdown voltage (On-BV) are important indicators. The off-state breakdown voltage and on-state breakdown voltage have a great relationship with the doping concentration of the drift region of the device, however, due...

AI Technical Summary

Problems solved by technology

The off-state breakdown voltage and on-state breakdown voltage have a great relationship with the doping concentration of the drift region of the device, however, due to the different positions of the strongest point of impact ionization in the on-state breakdown and off-state breakdown states of the device , the existing means are difficult to meet the needs of increasing the breakdown voltage of the off-state and the breakdown voltage of the on-state at the same time

[0004] The semiconductor structure formed by the existing LDMOS device technology needs to be further improved

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