Demonstration of high mobility and quantum transport in modulation-doped β-(AlxGa1-x)2O3/Ga2O3 heterostructures

• Published in: Applied physics letters Vol. 112; no. 17
• Main Authors: Zhang, Yuewei, Neal, Adam, Xia, Zhanbo, Joishi, Chandan, Johnson, Jared M., Zheng, Yuanhua, Bajaj, Sanyam, Brenner, Mark, Dorsey, Donald, Chabak, Kelson, Jessen, Gregg, Hwang, Jinwoo, Mou, Shin, Heremans, Joseph P., Rajan, Siddharth
• Format: Journal Article
• Language: English
• Published: 23-04-2018
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.5025704

In this work, we demonstrate a high mobility two-dimensional electron gas (2DEG) formed
at the
β-(AlxGa1-x)2O3/Ga2O3
interface through modulation doping. Shubnikov-de Haas (SdH) oscillations were observed in
the modulation-doped
β-(AlxGa1-x)2O3/Ga2O3
structure, indicating a high-quality electron channel formed at the heterojunction
interface. The formation of the 2DEG channel was further confirmed by the weak temperature
dependence of the carrier density, and the peak low temperature mobility was found to be
2790 cm2/Vs, which is significantly higher than that achieved in bulk-doped
Beta-phase Gallium Oxide (β-Ga2O3). The observed SdH oscillations
allowed for the extraction of the electron effective mass in the (010) plane to be
0.313 ± 0.015 m0 and the quantum scattering time to be 0.33 ps
at 3.5 K. The demonstrated modulation-doped
β-(AlxGa1-x)2O3/Ga2O3
structure lays the foundation for future exploration of quantum physical phenomena and
semiconductor device technologies based on the β-Ga2O3 material
system.