Modulations in effective work function of platinum gate electrode in metal-oxide-semiconductor devices

Reduction in the accumulation capacitance value was more in Si metal-oxide-semiconductor devices than that of Ge metal-oxide-semiconductor devices after a thermal treatment irrespective of the annealing environment. Relatively, thermal treatment in oxygen environment improves the interface quality of HfO₂/Ge stacks considerably, when compared with HfO ₂/Si stacks. Whereas, the forming gas annealing at a temperature of 400 °C was not so effective in improving the interface quality at HfO ₂/Si stack. The presence of induced negatively charged hydrogen atom in Ge lessens the Fermi level pinning at HfO₂ and Ge interface.