The impact of deposition layer and annealing temperature towards BST thin film characteristics

Ferroelectric materials which consist of the complex oxides with perovskite structure provided multifunctional have been attracted the eyes of the researchers in the application of electronic and optical devices. The attractive part of these materials is the sensitivity on physical properties to temperature, external electrical, magnetic, and mechanical stress, particularly near the temperatures of phase transitions. Wide range of electronic applications make used of these ferroelectric materials due to its dielectric, electric, temperature, magnetic and optical properties. The properties in Barium Strontium Titanate (BST) thin film causing it become extensively studied and emerged in to the application in high density DRAM, microwave phase shifter, IR sensing, humidity and gas sensor, tunable filters, piezoelectric actuator, voltage controlled oscillators, and varactors. The aim for this study is to investigate the main effect interaction of the Bao.sSro.s Ti03 thin film number of deposition layer and annealing temperature in terms of microstructure and electrical properties to the BST. Besides that, to find the main effect relation of the electrical properties of the BST thin film. The study on the Bao.sSo.s Ti03 thin film is prepared using sol-gel technique on silicon substrate. Throughout the study, the BST solution is deposited on the Pt/Si02/Si substrate by spin coating method in order for the purpose of investigating the microstructure of the thin films. Moreover, all the samples are deposited with combination of 2 different deposition layer and annealing temperature. Physical and electrical characterization of all the samples is done. The results showed that the grain size and surface roughness of the samples increased from 38.67 to 90.78 and 1.92 to 9.41 , respectively as the deposition layer and annealing temperature increased. In addition, the dielectric constant of the samples also increased from 136.78 to 783.91 as the deposition layer and annealing temperature increased. Thus, the physical and electrical characteristics of the thin films are related on to another. This study has shown the effects of the deposition layer and annealing temperature of BST sol-gel thin films on the structure, microstructure and dielectric properties. A clear main effect between the surface roughness, grain size and the dielectric properties has been discovered in the BST sol-gel thin films. The objectives achieved where the increase in deposition layer and heat treatment temperature increased the crystallinity, grain size, surface roughness and contribute to the non-ferroelectric materials such as grain boundaries. This resulted in the direct effect on the increase of the thin film dielectric constant and tunability.