Gaussian distribution on electrical properties of identically fabricated Au/n-GaN Schottky junctions with a Nd₂O₃ interfacial layer

This work emphasizes the twenty Au/Nd₂O₃/n-GaN MIS junctions identically fabricated using the e-beam evaporation technique. The electrical and interfacial properties of the identically prepared MIS junctions were investigated using current-voltage (I-V) measurements. The surface topology and chemical properties of the Nd₂O₃ film on the n-GaN were investigated using AFM and XPS techniques. The barrier height (Φ_b) and the ideality factor (n) of the twenty MIS junctions were estimated, revealing variability across different junctions. Using statistical analysis, the mean values of rectification ratio (RR), barrier height (Φ_b), ideality factor (n), series resistance (R_S) and shunt resistance (R_Sh) were estimated from I-V data based on thermionic emission (TE) theory. The fluctuations in the electrical parameters are attributed to an inhomogeneous interfacial layer and barrier height, as well as the non-uniformity of interfacial traps, dislocations and grain boundaries. The laterally homogeneous Φ_b was also estimated for the twenty MIS junctions from the linear association between the experimental n and Φ_b. The lateral inhomogeneity of Φ_b was clarified by examining the correlation between n and Φ_b of the identically prepared MIS junctions. Further, the mean interface state density (N_SS) was determined for the MIS junctions.