Demonstration of n-Ga2O3/p-GaN diodes by wet-etching lift-off and transfer-print technique

In this paper, a 400-nm-thick β-Ga2O3 nanomembrane is extracted from an n-Ga2O3-on-silicon wafer by wet etching, and then transferred to a p-GaN/sapphire wafer by transfer-print technique to fabricate n-Ga2O3/p-GaN heterojunction diodes. X-ray photoelectron spectroscopy (XPS) measurement is used to accurately confirm that the valence-band offset of the heterojunction is 1.41±0.07 eV. The diodes exhibit excellent electrical properties including high rectification ratio (3.85×106 at ±5 V) and low reversed current density (1.51×10-7 A·cm-2 at -5 V). The results show that the lift-off and transfer-print processes pave a new way for fabricating high-performance Ga2O3-based heterojunctions and bipolar devices.