Impact of Nitrogen Doping on Leakage Current of p‐Type Cu ₂ O‐Based pn Junctions for Ga ₂ O ₃ Power Device Applications

This study investigates the effects of nitrogen doping on the structural, optical, and electrical properties of Cu ₂ O and N‐doped Cu ₂ O films deposited by RF magnetron sputtering using Cu or Cu ₂ O targets under varying nitrogen flow conditions. X‐ray diffraction and transmission electron microscopy analyses reveal that nitrogen doping alters the polycrystalline orientation, particularly the (111) planes. The stability of the Cu ₂ O phase across all the doping is confirmed by Raman spectroscopy. Optical bandgap estimates using Tauc's plots that shows ≈2.5 eV, implying that the doping does not significantly affect the band structure of Cu ₂ O. Electrical properties of Cu ₂ O and N‐doped Cu ₂ O demonstrate that the nitrogen doping increases hole density while reducing Hall mobility, with the effect being more pronounced in the films deposited using the Cu target. Device properties indicate a correlation between polycrystalline orientation and leakage current, with better control of orientation and lower leakage current observed in films deposited using the Cu ₂ O target. Reverse voltage of N‐doped Cu ₂ O Films (N ₂ = 1%) using Cu ₂ O target shows 1024 V, where the strong preferred orientation of <111> is clearly observed. These findings provide valuable insights into optimizing nitrogen‐doped Cu ₂ O films for improved performance in electronic applications.