Ni(Pt) germanosilicide contacts formed on heavily boron doped Si_(1-x)Ge_x substrates for Schottky source/drain transistors

摘要

The electrical properties of Ni_(0.95)Pt_(0.05)-germanosilicide/Si_(1-x)Ge_x contacts on heavily doped p-type strained Si_(1-x)Ge_x layers as a function of composition and doping concentration for a given composition have been investigated. A four-terminal Kelvin-resistor structure has been fabricated by using the conventional complementary metal-oxide-semiconductor (CMOS) process to measure contact resistance. The results showed that the contact resistance of the Ni_(0.95)Pt_(0.05)-germanosilicide/Si_(1-x)Ge_x contacts slightly reduced with increasing the Ge fraction. The higher the doping concentration, the lower the contact resistivity. The contact resistance of the samples with doping concentration of 4 × 10~(19) cm~(-3) is nearly one order of magnitude lower than that of the samples with doping concentration of 5 × 10~(17) cm~(-3). In addition, the influence of dopant segregation on the contact resistance for the lower doped samples is larger than that for the higher doped samples.