Effect of Rapid Thermal Annealing on the Electrical and Structural Properties of Se Schottky Contacts to n-Type Si
V. Janardhanam, Yeon-Ho Kil, Kyu-Hwan Shim, V. Rajagopal Reddy, Chel-Jong Choi
We have investigated the electrical and microstructural properties of Se Schottky contacts to n-type Si before and after rapid thermal annealing (RTA) at temperatures in the range of 100–200°C for 30 s under N2 ambient. The forward and reverse leakage currents increased with increasing RTA temperature following which the barrier heights decreased from 0.71 to 0.60 eV before and after annealing at 200°C. With increasing RTA temperature, the crystallization of the Se film proceeded and the film was fully crystallized after being annealed at 200°C without the reaction between Se film and Si substrate. The decrease in the barrier height of Se Schottky contacts to n-type Si with increasing RTA temperature could be associated with the decrease in series resistance caused by the phase transformation from high resistance amorphous Se to low resistance crystalline Se. An investigation of the reverse current–voltage characteristics of Se/n-type Si Schottky contacts showed that the Schottky emission mechanism dominates the current transport in the reverse bias at all annealed temperatures in the range of 100–200°C.