A kind of Gan-based heterojunction diode and its preparation method

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 grown sequentially on a substrate; In the groove area, the high hole concentration structure layer covers the upper surface of the groove; the cathode electrode is located on the part of the upper surface of the barrier layer that is not covered by the high hole concentration structure layer; the first part of the anode electrode is located on the upper surface of the barrier layer and is not covered by the high hole concentration layer. Another part of the area covered by the concentration structure layer is located next to the high hole concentration structure layer; the second part of the anode electrode covers the upper surface of the high hole concentration structure layer; the passivation protection layer covers the upper surface of the barrier layer and is not covered by the cathode The area covered by electrodes and anode electrodes. The invention has high reliability and good repeatability, can realize the adjustment of the opening voltage of the device, and obtains a GaN heterojunction diode with low opening voltage and low reverse leakage current.

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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