Heterojunction p-Cu2O/n-Ga2O3 diode with high breakdown voltage

Abstract

Heterojunction p-Cu2O/n-β-Ga2O3 diodes were fabricated on an epitaxially grown β-Ga2O3(001) layer. The reverse breakdown voltage of these p-n diodes reached 1.49 kV with a specific on-resistance of 8.2 mΩ cm2. 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/cm2 indicated the lower conduction band offset at the hetero-interface between Cu2O and Ga2O3 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 Ga2O3 to achieve higher breakdown voltage and lower on-resistance.

Electrical Properties of Vertical p‐NiO/n‐Ga2O3 and p‐ZnCo2O4/n‐Ga2O3 pn‐Heterodiodes

“…The layer thicknesses used in this study are not sufficient to determine a breakdown field. However, the reverse voltages discussed here are much lower than breakdown voltages mentioned in the literature for pn‐heterodiodes or Schottky barrier diodes . In order to achieve such high breakdown voltages, thicker Ga 2 O 3 layers or a lower doping could be used.…”

“…The Cu 2 O/Ga 2 O 3 heterodiodes were fabricated on commercially available epitaxial n‐Ga 2 O 3 on Ga 2 O 3 substrates. A direct comparison of Cu 2 O/Ga 2 O 3 heterodiodes with platinum Schottky diodes on one and the same thin film was reported . The pn‐heterodiodes and the platinum Schottky diodes exhibit breakdown voltages of 1.49 and 0.67 kV, respectively.…”

“…Besides high power applications, Ga 2 O 3 and its alloys are suited for solar‐blind photo detection, realized so far by Schottky barrier metal‐semiconductor‐metal structures . However, heterojunction diodes comprising group‐III sesquioxides were also reported in terms of NiO/Ga 2 O 3 , Cu 2 O/Ga 2 O 3 , NiO/In 2 O 3 , and ZnCo 2 O 4 /In 2 O 3 pn‐heterostructures . In case of NiO/Ga 2 O 3 , the p‐type layer was Li‐doped and grown by the sol‐gel method on (100) β ‐Ga 2 O 3 single crystals with a free electron concentration of 5 × 10 17 cm −3 .…”

An Overview of the Ultrawide Bandgap Ga2O3 Semiconductor-Based Schottky Barrier Diode for Power Electronics Application

“…Ga 2 O 3 SBD starts to present its potential in power electronics applications.

Fig. 4The development of Ga 2 O 3 SBD in recent years [16, 18, 62, 68–71]

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“…In 2017, T. Watahiki et al from Mitsubishi Electric Corporation reported a heterojunction p-Cu 2 O/n-Ga 2 O 3 p-n diode without local termination structure [71]. Figure 11 shows the schematic, band diagram and J–V curves of this p-n diode.…”