GaN-based heterojunction diode and preparation method thereof

Abstract

The invention discloses a GaN-based heterojunction diode and a preparation method thereof. The GaN-based heterojunction diode comprises a GaN intrinsic layer and a barrier layer which sequentially grow on a substrate; one part of groove area is formed in one part of barrier layer; a high-hole concentration structure layer covers the upper surface of a groove; a cathode electrode is located in onepart of area, which is not covered with the high-hole concentration structure layer, on the upper surface of the barrier layer; a first part of an anode electrode is located in the other part of area,which is not covered with the high-hole concentration structure layer, on the upper surface of the barrier layer and the position of the first part is next to the high-hole concentration structure layer; a second part of the anode electrode covers the upper surface of the high-hole concentration structure layer; and a passivation protection layer covers an area, which is not covered with the cathode electrode and the anode electrode, on the upper surface of the barrier layer. The GaN-based heterojunction diode is high in reliability and good in repeatability, adjustment of threshold voltage of the diode can be achieved, and the GaN-based heterojunction diode with low threshold voltage and low reverse leakage current is obtained.

Description

technical field [0001] The invention relates to the technical field of manufacturing semiconductor devices, in particular to a GaN-based heterojunction diode with a p-type multi-component nitride alloy with a gradual change in composition added to a GaN heterojunction structure and a preparation method thereof. Background technique [0002] GaN material has unique advantages in the preparation of high-voltage, high-temperature, high-power and high-density integrated electronic devices because of its large band gap, high critical breakdown electric field, and high thermal conductivity. [0003] GaN materials can form heterojunction structures with AlGaN, InAlN and other materials. Due to the spontaneous polarization and piezoelectric polarization effects of materials such as AlGaN or InAlN, a high-concentration and high-mobility two-dimensional electron gas (2DEG) will be formed at the heterojunction interface. This characteristic can not only improve the carrier mobility an...

AI Technical Summary

Problems solved by technology

Due to the limitation of the Schottky barrier of conventional GaN Schottky diodes, the forward turn-on voltage is generally fixed at about 1V and cannot be adjusted.

[0006] 2. Large reverse leakage current

[0007] In response to these shortcomings, the researchers proposed to use high and low work function metal layer mixed anodes, F ion implantation technology under the Schottky, and groove anodes to make Schottky diodes, which can effectively reduce the turn-on voltage of Schottky diodes. However, it cannot effectively reduce the reverse leakage current of the device, effectively reduce the turn-on voltage and reverse leakage current of GaN diodes, and increase the breakdown voltage has become the main problem to be solved.

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