Heterojunction p-Cu_2O-Ga_2O_3 diode with high breakdown voltage

摘要

Heterojunction p-Cu_2O-β-Ga_2O_3 diodes were fabricated on an epitaxially grown β-Ga_2O_3(001) layer. The reverse breakdown voltage of these p-n diodes reached 1.49 kV with a specific on-resistance of 8.2 mΩ cm~2. The leakage current of the p-n diodes was lower than that of the Schottky barrier diode due to the higher barrier height against the electron. The ideality factor of the p-n diode was 1.31. It indicated that some portion of the recombination current at the interface contributed to the forward current, but the diffusion current was the dominant. The forward current more than 100 A/cm~2 indicated the lower conduction band offset at the hetero-interface between Cu_2O and Ga_2O_3 layers than that predicted from the bulk properties, resulting in such a high forward current without limitation. These results open the possibility of advanced device structures for wide bandgap Ga_2O_3 to achieve higher breakdown voltage and lower on-resistance.