ویژگی دی الکتریک تیتانات زیرکونیوم به وسیله واکنش گر Co-Sputtering
Abstract
1- Introduction
2- Experimental Details
3- Results and Discussion
4- Conclusions
References
ABSTRACT
Zirconium titanate thin films were deposited on alumina substrates by DC magnetron reactive co-sputtering by varying substrate temperature and the effects of substrate temperature on optical and dielectric properties of the films have been studied intensively by available characterization techniques. The optical parameters were determined by Swanepoel’s method. The films exhibited high transmittance in the visible region and the optical band gap of the films varied from 3.1 to 2.8 eV as the temperature varied from 33 to 400o C. The film deposited at room temperature exhibit a high transmittance of 71%. Dielectric constant measurements have been carried out at 10 GHz of frequency. The dielectric constant increased with increase in temperature and the film deposited at 400o C exhibited a high dielectric constant (40) and a low dielectric loss (0.026).
INTRODUCTION
HIGH-K dielectric materials find applications in dielectric resonators, filters, gate dielectrics, phase shifters, voltage tunable oscillators and dynamic random access memories [1]. Owing to their high dielectric constant, high quality factor, high temperature stability besides good optical properties Zirconium titanate (ZTO) and ZTO based materials act as potential candidates for microwave dielectrics [2-4] and also find applications in mid-infrared integrated photonics as well [5]. There are reports on the effects of processing parameters like substrate temperature [6], annealing temperature [7, 8] and partial pressure ratios of sputtering and reactive gases [4] on the dielectric properties of ZTO films. Some of the authors described correlation of processing parameters and film properties. Kim et al reported the effects of thickness on dielectric behavior of ZTO thin films fabricated by sol-gel process [9]. Kim et al demonstrated effects of microstructures on microwave dielectric properties of ZTO thin films [10]. Victor et al reported the significance of amorphous ZTO thin films and the dielectric relaxation phenomenon in these films [11]. Kim et al correlated strain and dielectric properties of ZTO thin films [1]. Kim et al described effects of substrate temperature on physical and dielectric properties of ZTO thin films in the MHz to GHz range by measuring dielectric constant in the range of 2 to 6 GHz [6, 10].