Amorphous Sr_0.8Bi_2.2Ta₂O₉ thin films for mim embedded capacitors

Sr_0.8Bi_2.2Ta₂O₉ (SBT) thin films with thickness a ranging from 77 nm to 107 nm were deposited on Pt/Ti/SiO₂/Si substrates by using a pulsed laser deposition method. During the deposition, the process substrate temperature was maintained at 350 °C for embedded capacitor applications. To form the top electrode of the MIM capacitor, we deposited Pt on the thin films by dc sputtering. The dielectric and the electrical properties of the SBT thin films were investigated in order to evaluate the performance for embedded MIM capacitors. A high capacitance density of 7.06 fF/μm², along with a dissipation factor of 2.68%, was obtained at 1 MHz. The linear and the quadratic voltage coefficients of the capacitance were 590 ppm/V and 196 ppm/V², respectively. These results demonstrate that the amorphous SBT thin films are good candidate materials for MIM embedded capacitor.