Low Turn-On Voltage and Reverse Leakage Current β -Ga 2 O 3 MIS Schottky Barrier Diodes With an AlN Interfacial Layer

作者：Zifan Hong, Chuanlun Zhang, Jialong Lin, Jianxun Dai, Jie Zhang, Huolin Huang, Weifeng Yang · 发表于：IEEE Transactions on Electron Devices · 年份：2024 · DOI：10.1109/ted.2024.3469909 · 被引用次数：21 · 研究领域：Ga2O3 and related materials、Electronic and Structural Properties of Oxides、Advanced Photocatalysis Techniques

We demonstrate for the first time a vertical metal/AlN/$\beta $-gallium oxide ($\beta $-Ga2O3) metal-insulator–semiconductor (MIS) Schottky barrier diode (SBD) with low turn-on voltage (${V}_{\text {on}}$) and reverse leakage current. By employing an ultrathin AlN layer enabled by atomic layer deposition (ALD), the resulting AlN/$\beta $-Ga2O3 MIS SBD exhibits a remarkably low leakage current of$0.1~\mu $A/cm2, which is three orders of magnitude smaller than that of the conventional$\beta $-Ga2O3 SBD. Meanwhile, the AlN/$\beta $-Ga2O3 MIS SBD shows a significantly improved breakdown voltage from 208 V up to 890 V, while maintaining a relatively low${V}_{\text {on}}$of 0.92 V andon-resistance (${R}_{\text {on}}$) of 11.8 m$\Omega \cdot $cm2, respectively. I–V measurements conducted across a range of temperatures from 298 to 432 K indicate that thermionic field emission (TFE) and trap-assisted tunneling (TAT) are the predominant electron transport mechanisms under forward bias if inserting 2 nm AlN, while TFE becomes dominant mechanism when the AlN thickness increases up to 5 nm. X-ray photoelectron spectroscopy (XPS) characterizations reveal the type I alignment for AlN/$\beta $-Ga2O3 heterojunction with a large conduction band offset ($\Delta {E}_{C}$) of 1 eV, which could function as an electron transport barrier under reverse conditions, thereby greatly suppressing the leakage current. Our study for the first time suggests a great potential for ALD-derived AlN films to be a...