High-performance three-terminal fin field-effect transistors fabricated by a combination of damage-free neutral-beam etching and neutral-beam oxidation

Three-terminal fin field-effect transistors (3T-FinFETs) were fabricated by neutral-beam oxidation (NBO) to form gate silicon dioxide (SiO₂). The 3T-FinFET fabricated by NBO showed higher device performance-namely, a higher subthreshold slope and a higher effective mobility-than that fabricated by conventional thermal oxidation. It is considered that those improved subthreshold slope and mobility are due to the fact that the three-dimensional structure of a SiO₂ film fabricated by NBO has a lower interfacial state density and a lower roughness than a similar structure fabricated by the conventional thermal oxidation of a SiO₂ film. The reasons for the lower interfacial state density and lower roughness are the low temperature and lattice plane independence of NBO in comparison with conventional thermal oxidation processes.