GaN-based vertical diode and preparation method thereof

Abstract

The invention provides a GaN-based vertical diode and a preparation method thereof. The preparation method comprises the steps: S1, sequentially growing an n-GaN layer and an AlGaN layer on a GaN substrate; S2, growing a barrier layer on the AlGaN layer, etching the end part of the barrier layer and the end part of the AlGaN layer, and exposing the end part of the n-GaN layer; S3, sequentially injecting energy from low to high through oxygen ion injection, and forming a Ga2O3 high-resistance region at the end part of the n-GaN layer; S4, removing the barrier layer, and depositing an anode on the AlGaN layer; S5, depositing an oxide layer on the AlGaN layer, and forming a hole in the top of the oxide layer; and S6, depositing a cathode on the back surface of the GaN substrate. A large number of electrons are attracted through an oxygen ion implantation technology, so that an electric field is distributed more uniformly, the breakdown voltage is improved, a 5nm n-AlGaN thin layer grows epitaxially, the current transport capacity is enhanced through a polarization effect, and the SBD breakdown voltage is improved by adopting an oxide layer terminal structure.

Description

technical field [0001] The invention belongs to the field of semiconductor devices, in particular to a GaN-based vertical diode and a preparation method thereof. Background technique [0002] In vertical power rectifiers, GaN Schottky barrier diodes (SBDs) can provide low conduction / switching losses and high switching frequency due to their low forward voltage drop and fast reverse recovery characteristics. Meanwhile, GaN-on-GaN vertical devices can achieve high breakdown voltage (BV), high current capacity, low thermal resistance, and excellent dynamic performance, making them ideal for power electronics applications. Its structure and characteristics allow it to work stably in high-voltage, high-current output occasions and high-frequency environments. [0003] SBD has low power consumption, can operate at high voltage and high frequency, and has a small forward conduction voltage drop. It is mostly used in high-frequency, high-current rectifier diodes, freewheeling diode...

AI Technical Summary

Problems solved by technology

However, it is difficult to implement in vertical GaN devices due to the great challenges of selective p-doping and its activation

There are generally the following methods: (i) field plate structure and its combination with deep trenches; (ii) high-resistivity regions are formed on the periphery of the device by using high-dose ion implantation, but deep energy level traps may be formed; ( iii) Increasing the barrier height / thickness at the junction edge improves breakdown, but increases turn-on voltage

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