Electrical properties of SiGe nanowire following fluorine/nitrogen plasma treatment

Abstract

The improvements to electrical properties of SiGe nanowires by surface plasma treatment were investigated. Various durations of pre-oxidation with fluorine; ambients for post-nitridation plasma treatment, and annealing temperature after plasma treatment, 800–950°C, were applied. Pre-oxidation treatment using fluorine plasma; improved the conductance of SiGe nanowires because the Si–F binding energy created a more stable interface state than bare nanowire on the surface of SiGe. N2 plasma incorporated more N than does in NH3 plasma, and NH3 has the drawback of introducing electron traps, causing Si–H bonds to break in the subsequent annealing process. Since the reparation of surface defects by plasma treatment is valid, the high post-annealing temperature to reduce defect by re-crystallizing can be reduced. Hence, Ge diffusion at low post-annealing temperature did not reduce the high concentration of Ge at the SiGe nanowire surfaces.