Thermal stability study of Ni-Si silicide films on Ni/4H-SiC contact by in-situ temperature-dependent sheet resistance measurement

Abstract

We investigate the Ni-Si film silicidation process on 4H-SiC and Si substrates and compare the thermal stability of the films grown on each substrate. The Ni-Si films were subjected to rapid thermal annealing (RTA) in the temperature range 575 °C-975 °C for 90 s, and their thermal stability was characterized by in-situ temperature-dependent sheet resistance measurements at temperatures of 25 °C-550 °C. The sheet resistance of a 40 nm thick Ni film was observed to increase sharply above 330 °C in the Ni/Si (100) interface, but slightly decrease at approximately 480 °C in the Ni/4H-SiC interface. The thermal stability of the films was found to be significantly dependent on the RTA temperature. Thermally stable Ni-Si silicide films with excellent Ohmic properties (no hysteresis behavior) can be obtained on 4H-SiC substrates at RTA temperatures of 925 °C-975 °C and can used for application in MOSFET devices.