Structural, electrical, and surface morphological characteristics of rapidly annealed Pt/Ti Schottky contacts to n‐type InP

Abstract

AbstractWe have investigated the electrical and structural properties of Pt/Ti metallization scheme on n‐type InP as a function of annealing temperature using current–voltage (I–V), capacitance–voltage (C–V), Auger electron spectroscopy (AES), and X‐ray diffraction (XRD) measurements. Measurements showed that barrier height of as‐deposited Pt/Ti Schottky contact is 0.62 eV (I–V) and 0.76 eV (C–V). Experimental results indicate that high‐quality Schottky contact with barrier height and ideality factor of 0.66 eV (I–V), 0.80 eV (C–V), and 1.14 can be achieved after annealing at 400 °C for 1 min in N2 atmosphere. Further, it is observed that the barrier height slightly decreases to 0.55 eV (I–V) and 0.71 eV (C–V) after annealing at 500 °C. Norde method is also employed to calculate the barrier height of Pt/Ti Schottky contacts. The obtained values are in good agreement with those obtained by I–V measurements. These results indicate that the optimum annealing temperature for the Pt/Ti Schottky contact is 400 °C. According to AES and XRD analysis, the formation of indium phases at the Pt/Ti/n‐InP interface could be the reason for the increase of Schottky barrier height (SBH) after annealing at 400 °C. Results also showed the formation of phosphide phases at the interface. This may be the reason for the decrease in the barrier height after annealing at 500 °C. The AFM results showed that the overall surface morphology of Pt/Ti Schottky contact is reasonably smooth.