Effect of annealing on the electrical and interface properties of Au/PVC/n-InP organic-on-inorganic structures

Abstract

In this work, a thin polyvinyl chloride (PVC) is deposited on n-type InP substrate as an interfacial layer for electronic modification of Au/n-InP Schottky structure. The atomic force microscopy (AFM) results show that there is no significant degradation in the surface morphology of the PVC Schottky contact even after annealing at 200°C. The electrical parameters of Au/PVC/n-InP are calculated by current–voltage (I–V) and capacitance–voltage (C–V) techniques as a function of annealing temperature. Results show that the Au/PVC/n-InP structure exhibits an excellent rectifying behavior. The extracted barrier height (BH) of as-deposited Au/PVC/n-InP Schottky contact is 0.78eV (I–V) and 0.87eV (C–V). However, it is noted that the BHs increases to 0.85eV (I–V) and 0.96eV (C–V) upon annealing at 100°C and then slightly decreases after annealing at 200°C. Results indicate that the PVC film increases the effective barrier height by influencing the space charge region of the Au/n-InP junction. The series resistance of the Au/PVC/n-InP structure is extracted by Cheung’s method. The interface state density (Nss) as determined by Terman’s method is found to be 2.018×1012 and 1.599×1012eV−1cm−2 for the as-deposited and 100°C annealed Au/PVC/n-InP Schottky contacts, respectively. The experimental observations reveal that the Au/PVC/n-InP Schottky diode parameters change with increasing annealing temperature.