Manufacturing method of trench metal oxide semiconductor barrier Schottky diode device

Abstract

The invention discloses a manufacturing method of a trench metal oxide semiconductor barrier Schottky diode device. The method comprises the following steps: providing a wafer substrate; forming an epitaxial layer on the wafer substrate; forming a plurality of groove type polycrystalline structures at intervals in the epitaxial layer; forming a surface film layer on the epitaxial layer; performing ion sputtering to form a metal film layer on the surface film layer, wherein first processing is performed on the epitaxial layer so as to increase the pressure stress of the epitaxial layer on the wafer substrate, and / or second processing is performed on the surface film layer so as to increase the density of the surface film layer. According to the method provided by the invention, by increasing the pressure stress of the epitaxial layer on the wafer substrate and / or increasing the density of the surface film layer, the tensile stress generated by forming the metal film layer through subsequent sputtering is counteracted and / or the stress strain resistance of the wafer is enhanced, the buckling deformation of the wafer is avoided, and the flatness of the wafer is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for manufacturing a trench metal oxide semiconductor barrier Schottky diode device. Background technique [0002] Trench MOS Barrier Schottky Diodes (TMBS) device is a power device that introduces a trench MOS gate structure, which reduces the electric field at the Schottky barrier by using the "charge coupling" effect Intensity, thereby reducing the forward conduction voltage drop, while obtaining a lower reverse leakage current. In practical applications such as freewheeling diodes, smartphone chargers, and solar cells, the lower the forward voltage drop and reverse leakage current of TMBS, the lower the power loss and the higher the efficiency. [0003] In order to further improve the performance of the TMBS device, it is necessary to increase the thickness of the metal aluminum layer sputtered on the surface of the TMBS wafer (for example, from 4.5 μm to 6 μm...

AI Technical Summary

Problems solved by technology

However, in actual production, when the sputtered metal aluminum layer is thickened, the flatness of the wafer is reduced, and there is a warp around the center of the circle, resulting in out-of-focus during exposure and unable to work, and the wafer cannot be produced normally.

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