# Effects of O2/Ar Ratio on Preparation and Dielectric Properties of CaZrO3 Films by Radio Frequency (RF) Magnetron Sputtering

## TL;DR

This paper studies how changing the oxygen to argon ratio affects the structure and electrical properties of CaZrO3 thin films made using sputtering.

## Contribution

The study reveals how adjusting the O2/Ar ratio influences the formation of perovskite phases and dielectric performance in CaZrO3 films.

## Key findings

- Higher O2/Ar ratios promote the perovskite CaZrO3 phase in annealed films.
- A 40:40 O2/Ar ratio yields a high dielectric constant of 25 and low leakage current.
- Films with 40:40 O2/Ar show a temperature coefficient of permittivity under 122.7 ppm/°C.

## Abstract

CaZrO3 (CZO) thin films were deposited on Pt/Ti/SiO2/Si substrates at 450 °C by radio-frequency magnetron sputtering technology. The microstructures and dielectric properties of CZO thin films were investigated. X-ray diffraction analysis reveals that the perovskite orthogonal CZO phase would be promoted by a higher O2 partial pressure in the flow ratio of O2/Ar after thin films were annealed at 700 °C for 3 h in air. The films prepared under the flow ratio of O2/Ar (20:40, 30:40 and 40:40) show the main perovskite crystal phase of CaZrO3 with a small amount of Ca0.2Zr0.8O1.8. The main crystal phase was Ca0.2Zr0.8O1.8 when the film was deposited under an O2/Ar ratio of 40:10. The annealed film with a 40:40 O2/Ar ratio exhibits a dielectric performance with a high dielectric constant (εr) of 25 at 1 MHz, a temperature coefficient of permittivity of not more than 122.7 ppm/°C from 0 °C to 125 °C, and a low leakage current density of about 2 × 10−7 A/cm2 at 30 V with an ohmic conduction mechanism.