Power device structure with ESD and preparation method thereof

Abstract

The invention provides a power device structure with an ESD and a preparation method thereof. The device comprises 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, wherein the first groove and the second groove are distributed in the N-type epitaxial layer at intervals, a gate oxide layer and polycrystalline silicon ESD are arranged in the first groove, and a P-type doped region is formed in the polycrystalline silicon ESD; a gate oxide layer and a polycrystalline silicon gate are arranged in the second groove; the P-type body region is located in the N-type epitaxial layer between the grooves; the dielectric layer covers the first groove, the second groove and the P-type body region; the hole leading-out region is positioned in the dielectric layer and is electrically contacted with a P-type doped region and a P-type active region of the polycrystalline silicon ESD and an N-type active region in a P-type body region between the first groove and the second groove; and the metal electrode is located on the dielectric layer. The area of the ESD structure can be effectively reduced, the process planarization is facilitated, the device preparation cost is reduced, and the ESD leakage performance is improved.

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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