Impact of Post-Deposition Annealing on Electrical Properties of RF-Sputtered Cu2O/4H-SiC and NiO/4H-SiC PiN Diodes.

This study investigated the impact of the post-deposition annealing (PDA) process on the material and electrical properties of copper oxide (Cu₂O) and nickel oxide (NiO) thin films deposited on a silicon carbide (SiC) substrate. Through radiofrequency (RF) sputtering, these films were subjected to PDA in a nitrogen (N₂) and oxygen (O₂) gas environment. Remarkably, the Cu₂O films resisted phase transition following the N₂ PDA process but exhibited a transition to cupric oxide (CuO) after undergoing the O₂ PDA process. The symmetry of Cu 2p in the as-deposited Cu₂O film was excellent; however, the phase-transformed CuO films exhibited an increase in binding energy and the emergence of satellite peaks. The Ni 2p exhibited various defects, such as nickel vacancies (V_Ni) and interstitial oxygen (O_i), in response to the different PDA atmospheres. The rectification ratios of the N₂-annealed Cu₂O and NiO devices were determined as 1.50 × 10⁷ and 4.01 × 10⁶, respectively, signifying a substantial enhancement by a factor of approximately 789 for the Cu₂O/SiC device and 124 for the NiO/SiC device relative to their non-annealed counterparts. The findings of this study indicate that meticulous control of deposition for potential p-type materials such as Cu₂O and NiO can significantly improve the performance in applications involving high-throughput and low-cost electronics. [ABSTRACT FROM AUTHOR]