High Performance Metal-Insulator-Metal SrTiO₃ Thin Film Capacitors Integrated on 300 mm Si Wafers for Advanced Technology Nodes

Paraelectric Strontium titanate (SrTiO₃) perovskite thin films have recently gained attention in the semiconductor industry. This is due to their high dielectric constant of &gt; 100 at room temperature, low dielectric loss and non-toxicity due to the absence of Lead^1,2. Thin films of SrTiO₃on various electrodes are being studied world-wide to demonstrate practical usage in the domain of Metal-insulator-metal (MIM) capacitors^3,4. In this work we demonstrate a high performing two plate MIM capacitor utilizing the SrTiO₃film integrated on a 300 mm Silicon (Si) wafer. Highly crystalline SrTiO₃film was grown on crystalline Ruthenium (Ru) electrode using an advanced sputter technique. The complete stack is made of Ru/ SrTiO₃/ Ru thin films, where both the top and bottom Ru electrodes and a (200) oriented SrTiO₃dielectric film were deposited utilizing back-end of line (BEOL) compatible conditions. Following the completion of the deposition step on the 300 mm Si wafer, the MIM capacitor was integrated in the fabrication facility using a state-of-the-art integration flow. The resulting devices demonstrated a capacitance density of about 95 fF/um² with an average leakage of 2e^-5A/cm². This is a capacitance density boost of about 2.5 times compared to our previously reported MIM capacitor⁵. Furthermore, a record low equivalent oxide thickness (EOT) of about 0.4 nm has also been achieved with this MIM capacitor. The development of such a high performing capacitor together with the BEOL compatibility provides a significant advantage in lowering the voltage droop in a power delivery network without any significant area penalty in future technology nodes.<br/><br/>References:<br/>D. Fuchs <i>etal.,</i> J. Appl. Phys. 1999, 85, 7362−7369<br/>C. S. Kang <i>etal.</i>, Jpn. J. Appl. Phys. 1996, 35, 4890<br/>C. B. Kaynak <i>etal.</i>, Microelectronic Engg. 2011, 88, 1521-1524<br/>M. A. Pawlak <i>etal.</i>, Appl. Phys. Lett. 2020, 97, 162906<br/>C-Y. Lin <i>et al</i>.,<i> IEEE Intl. Rel. Phys. Symposium</i>, 2020, pp.1-4