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

We 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 N 2 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.