Power device structure with esd and preparation method thereof

Abstract

The invention provides a power device structure with ESD and a preparation method thereof. The device includes an N-type substrate, an N-type epitaxial layer, a first groove, a second groove, a P-type body region, a P-type active region, an N-type active region, a dielectric layer and a metal electrode, the first groove and the The second trenches are distributed at intervals in the N-type epitaxial layer. The first trench includes a gate oxide layer and a polysilicon ESD, and a P-type doped region is formed in the polysilicon ESD; the second trench includes a gate oxide layer and a polysilicon gate. The P-type body region is located in the N-type epitaxial layer between the trenches; the dielectric layer covers the first trench, the second trench and the P-type body region; the hole lead-out region is located in the dielectric layer and is connected to the polysilicon ESD The P-type doping region, the P-type active region, and the N-type active region in the P-type body region between the first trench and the second trench are in electrical contact; the metal electrode is located on the dielectric layer. The invention can effectively reduce the area of ​​the ESD structure, is beneficial to process planarization and reduces device manufacturing cost, and helps to improve ESD leakage performance.

Description

technical field [0001] The present invention relates to the technical field of semiconductor devices, in particular to a power device, in particular to a structure of a power device with ESD (Electro-Static discharge, electrostatic discharge) and a preparation method thereof. Background technique [0002] Power devices, also known as electronic power devices, are widely used in various consumer electronic equipment and industrial equipment. During the working process of power devices, there is usually a large electric field intensity and current density, which will generate static electricity. If the static electricity cannot be effectively released, it will cause breakdown of the device, shorten the service life of the device, and even cause the device to burn out in severe cases. And cause serious production and life accidents. Therefore, current power devices usually have their own electrostatic protection devices, such as existing trench MOS devices with ESD such as fi...

AI Technical Summary

Problems solved by technology

However, the electrostatic discharge capability of the Zener diode is limited, which is far lower than that of the parasitic triode, and the Zener diode usually has a capacitance of tens of pF, which is easy to cause signal distortion

In addition, the polysilicon ESD layer is placed on the silicon surface, which affects the planarization of the process; the reverse bias leakage of polysilicon ESD is much higher than that of single crystal PN

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