Probing Charge Transport and Background Doping in Metal‐Organic Chemical Vapor Deposition‐Grown (010) β‐Ga2O3
Abstract
A new record‐high room‐temperature electron Hall mobility (μRT = 194 cm2 V−1 s−1 at n ≈ 8 × 1015 cm−3) for β‐Ga2O3 is demonstrated in the unintentionally doped thin film grown on (010) semi‐insulating substrate via metal‐organic chemical vapor deposition (MOCVD). A peak electron mobility of ≈9500 cm2 V−1 s−1 is achieved at 45 K. Further investigation on the transport properties indicates the existence of sheet charges near the epilayer/substrate interface. Si is identified as the primary contributor to the background carrier in both the epilayer and the interface, originating from both surface contamination and growth environment. The pregrowth hydrofluoric acid cleaning of the substrate leads to an obvious decrease in Si impurity both at the interface and in the epilayer. In addition, the effect of the MOCVD growth condition, particularly the chamber pressure, on the Si impurity incorporation is studied. A positive correlation between the background charge concentration and the MOCVD growth pressure is confirmed. It is noteworthy that in a β‐Ga2O3 film with very low bulk charge concentration, even a reduced sheet charge density plays an important role in the charge transport properties.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 08, 2020
- Source ID
- 10.1002/pssr.202000145
Entities
People
- A F M Anhar Uddin Bhuiyan
- Aaron R. Arehart
- David R. Daughton
- Hongping Zhao
- Joe F. McGlone
- Siddharth Rajan
- Steven A. Ringel
- Wyatt Moore
- Zhanbo Xia
- Zhaoying Chen
- Zixuan Feng
Organizations
- Air Force Office of Scientific Research
- National Science Foundation
- Ohio State University