Effects of ozone post deposition treatment on interfacial and electrical characteristics of atomic-layer-deposited Al2O3 and HfO2 films on GaSb substrates

摘要

Atomic-layer-deposited Al2O3 and HfO2 films on GaSb substrates were treatedby in-situ ozone post deposition treatment (PDT). The effects of ozone PDT onthe interfacial and electrical properties of Al2O3 and HfO2 gate dielectricfilms on GaSb substrates were investigated carefully. It is found that thedielectric quality and the interfacial properties of the Al2O3 and HfO2 filmsare improved by ozone PDT. After in-situ ozone PDT for 5 min, the Al2O3 andHfO2 films on GaSb substrates exhibit improved electrical and interfacialproperties, such as reduced frequency dispersion, gate leakage current, bordertraps and interface traps. Interface trap density is reduced by ~24% for theAl2O3/GaSb stacks and ~27% for the HfO2/GaSb stacks. In-situ ozone PDT isproved to be a promising technique in improving the quality of high-k gatestacks on GaSb substrates.