GaN-based heterojunction schottky diode device and preparing method thereof

Abstract

The invention relates to a GaN-based heterojunction schottky diode device and a preparing method thereof. The GaN-based heterojunction schottky diode device comprises a substrate and an epitaxial layer which grows on the substrate, wherein the epitaxial layer comprises a stress buffer layer, a GaN layer and a heterostructure barrier layer which are arranged from bottom to top. The anode area of the epitaxial layer is etched for forming a recessed trough. A low work function metal layer is plated on the recessed trough and partial surface of the heterostructure barrier layer through vapor plating. A high work function metal layer is plated above the low work function metal layer and the planar area of the heterostructure barrier layer through vapor plating. The high work function metal layer and the low work function metal layer form a mixed anode. Ohmic metal is plated on the cathode area through vapor plating for forming a cathode. The epitaxial layer is integrally covered by a passivation insulating layer. The insulating layer is etched for forming an electrode window. According to the GaN-based heterojunction schottky diode device, combination of mixed anode metal and anode recessed trough technique is realized; current under forward bias is activated in advance through the side wall of the anode recessed trough; reverse leakage current is cut off through the high work function metal layer on the surface of the heterostructure barrier layer under reverse bias, thereby realizing separation of forward and reverse current channels, and achieving a technical object of the GaN-based heterojunction schottky diode device with low turn-on voltage and low reverse leakage current.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a GaN-based heterojunction Schottky diode device and a manufacturing method thereof. Background technique [0002] The third-generation wide-bandgap semiconductor materials represented by GaN have excellent material performance characteristics such as wide bandgap, high shock electric field strength, high saturation electron drift velocity, high thermal conductivity, and high concentration of two-dimensional electron gas at the heterogeneous interface. Compared with Si materials, GaN devices are more suitable for making power electronic devices with high power capacity and high switching speed. Compared with traditional Si devices, GaN devices can carry higher power density and have higher energy conversion efficiency, which can reduce the volume and weight of the entire system, thereby reducing system cost. Due to its superiority in electrical properties, GaN-based semicond...

AI Technical Summary

Problems solved by technology

Although the above method reduces the turn-on voltage for AlGaN / GaN-based Schottky diodes without affecting the reverse leakage current, due to the complex operation process and single process technology, there is still room for reduction in the modulation of turn-on voltage, and further technical means are urgently needed. improve

Images