LDMOS (Laterally Diffused Metal Oxide Semiconductor) device and manufacturing method thereof

Abstract

The embodiment of the invention discloses an LDMOS (Laterally Diffused Metal Oxide Semiconductor) device and a manufacturing method thereof. The LDMOS device comprises a substrate, wherein the substrate comprises a first trap region, a second trap region positioned in a surface of the first trap region, a doped region positioned in a surface of the second trap region, field oxide positioned on the periphery of the doped region and a drift region positioned at the lower part of the field oxide, wherein a drain region is positioned in a surface of the doped region, and a certain distance is arranged between an edge of the drain region and an edge of the drift region. According to the invention, since the distance between the edge of the drain region and the edge of the drift region is changed and increased, the resistance between the edge of the drain region and the edge of the drift region is increased, a current flow path between the edge of the drain region and the edge of the drift region is increased, the maintaining voltage of the device is improved, therefore when an ESD (Electrostatic Discharge) phenomenon occurs, current between the drain region and the drift region is not concentrated, the caloric power of the device is reduced so as to avoid burn-out of the device, and the withstanding capability of the LDMOS device to ESD is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, and more specifically, relates to an LDMOS device and a manufacturing method thereof. Background technique [0002] Electrostatic discharge (ESD) is a common natural phenomenon in daily life. The electrostatic discharge process can generate a large current in a short time. For example, the electrostatic discharge phenomenon (HBM for short) that occurs on the human body usually occurs within hundreds of nanoseconds. , the maximum current peak can reach several amperes, while in some other models, such as CDM (charged device model), MM (machine model), the electrostatic discharge occurs for a shorter time and generates a larger current, such a large current Passing through the integrated circuit in a short period of time will seriously exceed the maximum value that the circuit itself can withstand, resulting in serious physical damage to the integrated circuit, and in severe cas...

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Problems solved by technology

[0005] However, for high-voltage devices, their own operating voltage is very high, and the maintenance voltage is very low. It is difficult to use the above method to increase the maintenance voltage of high-voltage devices to the level required to resist ESD. The increase is no longer effective

[0006] LDMOS (Lateral Double-diffuse MOS) devices are commonly used in existing ESD protection devices, especially in high-voltage processes, but the conditions of large current stress generated in the ESD process However, LDMOS devices are easily damaged, especially in high voltage processes

[0007] In the prior art, in order to improve the anti-ESD capability of the LDMOS device, the area of ​​the LDMOS device is usually increased, that is, in the multi-finger structure, the number of LDMOS devices is increased. However, due to the low sustain voltage of the LDMOS device itself, this The effect of this method is not very ideal

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