Si-SiO₂ interface passivation by plasma NH₃ and atomic H

Plasma ammonia treatment at 400°C leads to de-passivation of a fully hydrogenated Si-SiO₂ interface, and to passivation of a fully de-hydrogenated Si-SiO₂ interface. Plasma NH₃ exposure causes irreversible Si surface damage and degradation of thermal stability. Atomic hydrogen exposure, although it results in similar effects on the Si-SiO₂ interface, does not introduce additional defects or a decrease of the Si surface thermal stability. The difference between plasma NH3 exposure and atomic H exposure is speculated to be due to either the nitridation of Si-SiO₂ interface or radiation damage resulting from plasma NH₃ exposure. EPR measurements indicate changes of the paramagnetic defect properties and an increase in the paramagnetic defect density generated by plasma NH₃ exposure.