Investigation of ZrGe Schottky source/drain contacts for Ge p-channel MOSFETs

Zirconium germanide (ZrGe) Schottky source/drain (S/D) contacts were fabricated on n-Ge substrates using direct sputter deposition of Zr. The electrical properties of ZrGe/n-Ge contact were investigated and an excellent Schottky characteristic with an electron barrier height of 0.59 eV was obtained, implying an extremely low hole barrier height of 0.07 eV. Using ZrGe as S/D, the operation of Schottky Ge p-channel metal-oxide-semiconductor field-effect transistor (MOSFET) was well demonstrated without any S/D impurity doping. Its good performance indicates that ZrGe is available to S/D in Schottky Ge p-MOSFET.