【Device Papers】Vertical diodes on n-type β-Ga₂O₃ using p-Cu₂O for heterojunction formation and edge termination

      Researchers from the Indian Institute of Technology Bombay have published a dissertation titled "Vertical diodes on n-type β-Ga₂O₃ using p-Cu₂O for heterojunction formation and edge termination" in Applied Physics Letters.

Abstract

      Lack of viable p-type doping in ultra-wide bandgap β-Ga₂O₃ necessitates the use of p-type materials to form p–n heterojunction diodes (HJDs). This study demonstrates a comparative electrical performance analysis of vertical heterojunction devices using p-type Cu₂O layers such as junction termination extension-Schottky barrier diodes (JTE-SBDs), p–n HJDs, and junction barrier Schottky diodes (JBSDs), along with control SBDs and SiO₂ field plate (FP) SBDs. Through electrical characterization and TCAD simulations, we show that the JTE-SBD gives the best performance parameters with a 2.5× increase in breakdown voltage (V_br = 656 V) with nearly matched differential specific on-resistance (R_on,sp = 1.73 mΩ cm²) compared to the control SBD due to improved edge electric field management, better than the FP-SBD and the JBSD, and without R_on,sp degradation observed in series resistance-limited HJD devices. The JTE-SBD demonstrates a Baliga's figure of merit of 0.24 GW/cm². The near-unity ideality factors and low turn-on voltages of the p-Cu₂O-based diodes further underscore its potential for enhancing β-Ga₂O₃ high-power diode performance, such as through effective edge electric field management shown through the JTE-SBDs in this work.

DOI：

https://doi.org/10.1063/5.0320766