Surface engineering of p-Cu2O for enhanced hole injection in p-Cu2O/β-Ga2O3 heterojunctions
Journal
Materials Science in Semiconductor Processing
Journal Volume
208
Start Page
110526
ISSN
13698001
Date Issued
2026-06-15
Author(s)
Kim, Minseok
Prasad, Chowdam Venkata
Park, Seung-Hyun
Choi, Jin-Woo
Kang, Hyeon-Do
Lee, Geon-Hee
Koo, Sang-Mo
Abstract
Copper(I) oxide (p-Cu2O) has recently been regarded as a promising p-type semiconductor candidate for fabricating β-Ga2O3-based heterojunction diodes (HJDs). However, its practical utility is often hindered by intrinsic defects, particularly copper (VCu) and oxygen vacancies (VO), that impair electrical conductivity and compromise interface stability. To overcome these limitations, we introduce a UV/ozone (UVO)-based interface engineering approach aimed at passivating VO, tuning copper oxidation states, and eliminating surface impurities in sputtered p-Cu2O films. The p-Cu2O/β-Ga2O3 HJDs subjected to UVO treatment exhibited significant performance gains, including a 47.6% decrease in specific on-resistance (Ron,sp) (from 97.72 to 46.47 mΩ cm2), reduced reverse leakage current, and an enhanced breakdown voltage (BV) from 700 V to 775 V. These improvements led to a maximum Baliga's figure-of-merit (BFOM) of 12.92 MW/cm2, marking a 257.76% increase compared to untreated samples. The observed enhancements are attributed to a dual mechanism involving the suppression of oxygen-related defects and a UVO-induced upward shift of the valence band maximum (VBM). This modification improved hole injection and interfacial transport. Overall, this study presents a straightforward yet effective route for integrating p-type oxides with ultrawide bandgap (UWBG) semiconductors, laying the groundwork for future advancements in heterostructure device engineering through targeted interface modifications.
Subjects
Breakdown voltage
Interface engineering
p-Cu2O
UV/Ozone
β-Ga2O3
Publisher
Elsevier Ltd
Type
journal article