Microstructural and chemical properties of high-k holmium oxide (Ho2O3) and its effect on interface properties and current transport process of Au/n-GaN/Ti/Al Schottky contact as an interlayer

To comprehend the effect of the e-beam deposited high-k holmium oxide (Ho2O3) on the electrical possessions of Au/n-GaN/Ti/Al Schottky contact (SC), Au/Ho2O3/n-GaN/Ti/Al MIS-type contact was created with a Ho2O3 interlayer. The microstructural and chemical possessions of Ho2O3 film were assessed using XRD, XPS, TEM and EDX approaches. XRD, XPS, TEM and EDX studies indicate that the Ho2O3 layer exists on the GaN. The electrical features of the SC and MIS contact were probed using I-V and C-V approaches. The MIS contact shows a notable rectifying manner with a lower reverse leakage current than the SC. The MIS contact exhibits superior Phi b (0.85 eV) than the SC (0.72 eV), indicating the Ho2O3 interlayer greatly rehabilitated the Phi b of the SC. Using I-V, C-V, Cheung's and Norde processes, Phi b , n, and RS of the SC and MIS contacts were estimated, and the estimated Phi b were well matched with each other, which signifying the techniques used here steadiness and validity. The MIS contact exhibits a lower magnitude of N SS compared to the SC, portentous that the presence of the Ho2O3 layer played a significant part in diminishing NSS. The log (I) versus log (V) of forward bias of the SC and MIS contact reveals the ohmic nature and space charge limited current (SCLC) at the lower bias and upper bias sections. The conclusions suggest that the Ho2O3 material has potential for building MIS/MOS devices.