# High Capacitance Density and Thermal Stability in Strontium

## TL;DR

Strontium titanate thin films show high capacitance and thermal stability, making them promising for advanced capacitor applications.

## Contribution

Demonstration of high capacitance density and thermal stability in strontium titanate thin films using magnetron sputtering.

## Key findings

- STO thin films achieved a capacitance density of 1688 pF/mm² with a breakdown field strength of 270 kV/mm.
- Films annealed at 650 °C maintained capacitance within ±15% across −55 °C to 125 °C.
- XRD analysis confirmed uniform polycrystalline STO films after thermal annealing.

## Abstract

Magnetron sputtering allows for the accurate estimation of film thickness. Strontium titanate (STO) thin films were deposited on Nb-doped STO substrates using radiofrequency magnetron sputtering technology. The microstructures and dielectric properties of STO thin films were investigated. X-ray diffraction (XRD) analysis indicates that uniform polycrystalline STO films were obtained after thermal annealing at 650 °C. The films exhibit a significant correlation between thickness, annealing temperature, and breakdown field strength. The optimal film with a thickness of 1150 nm achieves a capacitance density of 1688 pF/mm2 and a breakdown field strength of 270 kV/mm. Additionally, STO films annealed at 650 °C maintained their capacitance value within ±15% across a temperature range of −55 °C to 125 °C. These results highlight the potential of STO thin films for high-performance capacitor applications.