Effects of Postdeposition Annealing on the Electrical Properties of Cu₂O/4H–SiC PiN Diodes

Copper oxide (Cu 2 O) is a promising p‐type material owing to its high absorption coefficient, suitable bandgap width, chemical stability, nontoxicity, and abundance. In this study, the effect of postdeposition annealing (PDA) on the electrical properties of Cu 2 O thin films deposited on silicon carbide (SiC) substrates is investigated. The films are subjected to PDA using radio‐frequency sputtering at various temperatures in air. During PDA, the Cu 2 O films are maintained at <300 °C and transitioned to cupric oxide (CuO) at 400 °C. The as‐deposited Cu 2 O film exhibits a low oxidation peak (Cu 2+ ), whereas the phase‐transformed CuO films exhibit a higher binding energy with the emergence of satellite peaks. The rectification ratios of the Cu 2 O device annealed at 300 °C and CuO device annealed at 400 °C are determined as 2.02 × 10 7 and 1.01 × 10 5 , respectively, denoting the substantial enhancement of approximately 55.04 for the Cu 2 O/SiC device and degradation of approximately 0.28 for the CuO/SiC device relative to their non‐annealed counterparts. Therefore, in this study, the significant improvement in the performance of Cu 2 O thin films with the meticulous deposition control of potential p‐type materials, such as Cu 2 O and CuO, for high‐throughput and low‐cost electronic applications is demonstrated.