Metal-germanide Schottky Source/Drain transistor on Germanium substrate for future CMOS technology

Abstract

In this study, we survey Schottky diode property of both p-metal (Ni) germanide and n-metal (Zr, Er and Yb) germanide in contact with Ge (100). Our experimental results demonstrate that Φp values obtained for NiGe/n-Ge is - 0.07 eV, and Φn values for YbGe/p-Ge is 0.139 eV, the lowest hole barrier so far reported. In addition, NiGe Schottky source/drain p-MOSFET with HfO2/TaN gate stack and AlN/SiO2 stacked spacer were fabricated and measured. The drain current at VD = V G - Vth = - 1.5 V is ∼ 4.0 μA/μm of the gate length LG = 8 μm device. The Ion/Ioff ratio is ∼ 103, and sub-threshold swing is 137 mV/dec.