【International Papers】Cryogenic temperature operation of NiO/Ga₂O₃ heterojunction and Ni/Au Schottky rectifiers

日期：2024-12-26阅读：194

Researchers from the University of Florida have published a dissertation titled "Cryogenic temperature operation of NiO/Ga₂O₃ heterojunction and Ni/Au Schottky rectifiers" in AIP Advances.

The paper was selected as a “Featured”. Dr. Hsiao-Hsuan Wan of the University of Florida was the first author of the paper, and Prof. Stephen Pearton was the corresponding author.

Abstract

Vertical geometry NiO/Ga₂O₃ heterojunction (HJ) rectifiers and Ni/Au Schottky rectifiers fabricated on the same wafer and each with the same diameter (100 μm) were operated at 77–473 K to compare their capabilities in space-like environments. The HJ rectifiers suffer a 4-order reduction in forward current at 77 K due to the freeze-out of acceptors in the NiO, leading to MIS-type operation. By sharp contrast, the Schottky rectifiers have higher forward current and lower on-resistance at 77 K compared to 298 K due to improved carrier mobility. The on/off ratio of Schottky rectifiers at 77 K becomes similar to HJ rectifiers at 298–473 K. The reverse recovery time of Schottky rectifiers is reduced from 20 ns at 273 K to 16 ns at 77 K, while HJ rectifiers cannot be switched at this temperature. While the latter are superior for high-temperature applications, the former are better suited to cryogenic operation.

FIG. 1. Schematic of Schottky and heterojunction rectifiers fabricated on the same wafer. The latter incorporate a bilayer of NiO to create a p-n junction with the Ga₂O₃.

FIG. 2. NiO TLM I–V characteristics at room temperature and 77 K. (a) Room temperature measurement results before and after 77 K treatment. (b) The performance of NiO TLM at 77 K. (c) and (d) Simulated TLM I–V characteristics for NiO films at 298 and 77 K, respectively.

DOI：

doi.org/10.1063/5.0233627