Metalhyphen;oxidehyphen;semiconductor characteristics of chemical vapor deposited Ta2O5films

摘要

This letter describes the metalhyphen;oxidehyphen;semiconductor characteristics of chemical vapor deposited Ta2O5films. With the passivation of bottom ultrathin SiO2layer (sim;3.4 nm), an excellent interface (i.e., low fixed charge and interface state densities) has been achieved. In this study, different top dielectrics such as SiO2and Si3N4were used to be compatible with conventional polycrystalline Sihyphen;gate process. By using top dielectrics deposited on Ta2O5, such as SiO2and Si3N4, the leakage current is found to be greatly suppressed by three orders of magnitude for minus;Vg. For +Vg, the leakage current behaviors are believed to be governed by the Fowlerndash;Nordheim tunneling through the bottom SiO2layer. Under highhyphen;field stress, however, interface state generation was found to be enhanced with the presence of the top dielectric layer.