Effects of in-situ RF sputter and conventional HF cleaning on TiSi2 formation

Abstract

The formation of titanium silicide grown on the arsenic heavily doped silicon substrate with HF and in-situ RF cleaning was investigated using x-ray diffraction, auger electron spectroscopy, transmission electron microscopy, and secondary ion mass spectroscopy. HF cleaned samples showed that thin oxide exists at the interface and titanium reacted silicon through the oxide to form a silicide when heated to a temperature ranging from 750 similar to 850 degrees C. One of the notable features of HF cleaned sample was the local growth of C54-TiSi2 phase. This was due to high arsenic concentration (>10(20) cm(-3)) inside the TiSi2 layer and the existence of thin SiO2. However, the growth of titanium silicide was enhanced when the in-situ RF cleaning method was carried out. Sheet resistance of titanium silicide with the RF cleaning was about 10 times lower than the conventional HF cleaning method.