The comparison between Ta2O5 and Ti-doped Ta2O5 dielectrics

In this study, the Ti-doped high-k Ta2O5 (Ta2TiO7) dielectric on poly-silicon treated with post-rapid thermal annealing showed a higher effective dielectric constant, higher breakdown electric field, and smaller gate voltage shift than those of the Ta2O5 dielectric. After rapid thermal annealing, it not only can passivate the dangling bonds and defect traps in the high-k dielectric, but also have high dielectric constant and suppress the generation of interfacial layer to form the stronger bonding for quality improvements. The high-k Ta2TiO7 treated with post-RTA at 800 °C had the best dielectric performance among all the conditions. Incorporating some Ti content into the Ta2O5 dielectric made some improvements in the electrical performance and material quality. The Ta2TiO7 dielectric is a very promising high-k dielectric for the future thin film transistor applications.