Interface passivation by deuterium for nanoscale CMOS devices

Passivation of interfaces such as Si/SiO₂ and Si/HfO₂ (Si/high-k) by deuterium instead of hydrogen is getting significant attention for scaled CMOS devices. This paper introduces the various methods of deuterium incorporation at the interface including thermal annealing and deuterium implantation at the Si/SiO₂ interface when a thin oxide is grown on implanted silicon substrate. In case of annealing thermal budget is a limiting factor whereas for implantation, energy and implantation dose significantly influence the interface passivation. Interface passivation by hydrogen and deuterium implantation is discussed. Observed interface states at the Si/SiO₂ interface suggests an isotope effect where deuterium implanted devices yielded better interface results compared to that of hydrogen implanted devices. Transient enhanced diffusion of implanted hydrogen and deuterium is affected by the implantation damage.