Chemical and structural features of spin-coated magnesium oxide (MgO) and its impact on the barrier parameters and current conduction process of Au/undoped-InP Schottky contact as an interfacial layer

This work examines the structural and chemical characteristics of spin-coated magnesium oxide (MgO) on undoped InP (un-InP) and its effects on the barrier parameters and current transport phenomena in the Au/un-InP Schottky contact (SC). Using XRD and XPS, the structural and chemical features of MgO are assessed, confirming that the MgO was deposited on un-InP. The current-voltage (log(I)-V) features were measured for the SC and Au/MgO/un-InP metal/insulator/semiconductor (MIS)-type Schottky contact. The MIS contact revealed an excellent rectification behavior as compared to the SC. The calculated barrier height (Φb) was higher for the MIS contact (0.61 eV) than the SC (0.52 eV), which implies that the MgO interlayer influences the Φb of the SC. The Φb was also estimated using the Cheung's, Mikhelashvili and Norde procedures, the values are similar, indicating their stability and reliability. The acquired interface state density (NSS) of the MIS contact was less than the SC, proving that the MgO interlayer reduced the NSS. The ohmic behavior was observed in the lower bias region for the SC and MIS contacts, while the trap-free space-charge-limited current (SCLC) was noted in the moderate and upper bias regions of the MIS contact under forward bias. Poole-Frenkel emission (PFE) governs at a lower bias, while Schottky emission (SE) dominates at the upper bias of SC and MIS contacts under reverse bias. These findings demonstrate the potential application of MgO interlayer in advancing electronic devices. •Structural and chemical properties of MgO films are explored by XRD and XPS.•Electrical features of Au/un-InP Schottky contact and Au/MgO/un-InP HJ were investigated.•Higher barrier height is acquired for the HJ than the Schottky contact.•Interface state density of HJ is lesser as compared to the Schottky contact.•Current transport process was studied for the Schottky contact and HJ contacts.