High-temperature H2 anneal of interface defects in electron-beam-irradiated MNOS structures

Abstract
A thermal anneal technique is proposed to effectively remove electron beam irradiation damage in metal‐nitride‐oxide semiconductor structures. Using a high‐temperature (800–950 °C) H2 anneal treatment the SiO2 layer is impregnated with hydrogen after the nitride deposition. This leads to very low surface state densities for both thick‐oxide and thin‐oxide devices. After irradiation the device is given a mild heat treatment at 450 °C in an inert ambient. A complete removal of the radiation‐induced fixed charges and surfaces states is observed. The effectiveness of the high‐temperature H2 anneal is most pronounced for thin‐oxide MNOS structures. The technique is shown also to be effective in case of other types of ionizing radiation.