Schottky diode structure and manufacturing method thereof

Abstract

The invention discloses a junction barrier schottky diode. An N-conductive type first drift layer is arranged on the upper surface of a substrate; back surface ohmic contact metal is arranged on the lower surface of the substrate; a p+ ion injection region is formed on the upper surface of the first drift layer through ion injection; front surface schottky contact metal is on the first drift layerand the upper surface of the p+ ion injection region; an N-conductive type second drift layer is between the first drift layer and the front surface schottky contact metal; and a P++ injection regionis between the p+ ion injection region and the front surface schottky contact metal. According to the diode disclosed by the invention, after JTE and FLR are finished, an N-Sic epitaxial layer is manufactured on the upper surface, and the small-area P++ region is prepared through the N-epitaxial layer, so that the contact area of the schottky metal is enlarged, the forward current density is increased, and meanwhile, no influence is caused on the aspect of reverse voltage withstand; and in addition, the P type region in the N-SiC epitaxial layer is heavily doped, so that peak current can be increased, and the surge resistance of a device can be improved.

Description

technical field [0001] The invention relates to a junction barrier Schottky diode structure and a manufacturing process thereof. Background technique [0002] Compared with the first-generation semiconductor and the second-generation semiconductor, SiC material has the advantages of large band gap, high breakdown electric field, saturation drift speed and thermal conductivity, etc., and is widely used in the preparation of high temperature, high frequency, radiation resistance, High-power electronic devices and power electronic devices made of SiC materials have become a frontier research field in the field of semiconductors. [0003] JBS (junction barrier schottky, junction barrier Schottky diode) combines the high withstand voltage and low leakage current of PiN diodes and the ground conduction characteristics of Schottky diodes, and combines SiC materials with JBS structures to prepare SiC. JBS structures integrate SiC The electrical performance advantages of the materia...

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Problems solved by technology

[0006] 1. The JBS structure introduces p in the drift region + area, in the case of low voltage, the conduction current is mainly done by the Schottky, P + The introduction of the area will reduce the forward conduction current of the device and increase the on-resistance; however, increasing the Schottky area improves the forward conduction characteristics and at the same time weakens the reverse withstand voltage capability. There is a contradiction and compromise between the two. problems in

[0007] 2. The edge of the JBS device junction has an electric field concentration effect, which reduces the reverse withstand voltage capability of the device. In order to alleviate the electric field concentration, the edge terminal of the device needs to be optimized

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