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.