Study on Schottky barrier modulation of NiGe/Ge by ion-implantation after Germanidation technique

In this letter, the As⁺ implantation after Germanidation technique is comprehensively studied to modulate the Schottky barrier height of NiGe/Ge contact. With the optimized drive-in annealing temperature, ion-implantation energy and dose, the current characteristics of NiGe/p-Ge diode changes from Ohmic to well rectifying with I_on/I_off ratio over 10⁴, and the corresponding hole barrier height increases to 0.52eV, which indicates a low electron barrier of 0.14eV has been achieved by this technique. In addition, an Ohmic behavior is obtained on n-Ge substrate, verifying the effective modulation of the electron Schottky barrier. The results may provide the guideline for improvement the performance of Ge-based Schottky barrier nMOSFETs.