High-Performance Germanium pMOSFETs With NiGe Metal Source/Drain Fabricated by Microwave Annealing

A microwave annealing technique has been developed to fabricate superior NiGe/n-Ge Schottky junctions. The impacts of the microwave conditions on the electrical properties of NiGe/n-Ge Schottky junctions have been systematically investigated. It is found that the Schottky-barrier height for holes is significantly reduced to 0.03 eV, attributable to the suppression of metal-induced gap states-induced Fermi level pinning effect. As a result, the junction leakage of the NiGe metal source/drain (S/D) has been sufficiently reduced. An enhanced on current and a record high on/off ratio of 10
⁴
were achieved in the high-performance Schottky-barrier Ge pMOSFETs with a NiGe metal S/D formed by microwave annealing.