Electrode material influence on thin film BST ceramic capacitor

Abstract A metal-insulator-metal (MIM) parallel plate thin-film capacitor of ceramic dielectric was fabricated using an n-type silicon wafer substrate and characterized electrically. The ferroelectric perovskite BST36 (Ba 0.36 , Sr 0.64 )TiO 3 thin film dielectric was deposited via the RF magnetron sputtering technique, and the film is employed as a dielectric for the parallel plate ceramic capacitor. A molybdenum disilicide (MoSi 2 ) thin film has been deposited via the DC magnetron sputtering technique, and the sheet resistance was 5.611 Ωcm − 2 , after thermal processing. It has been used as a bottom metal contact for the device. While indium (In), copper (Cu), and silver (Ag) were deposited via the thermal evaporation technique and employed as top contact electrodes for the device. Molybdenum disilicide (MoSi 2 ) has been used again as a top contact electrode as well as a bottom electrode. The capacitor was electrically characterized at room temperature under a 10 VDC bias and 1 MHz frequency. Measurements of dielectric loss, dielectric constant, and capacitance density were depended on the device structure and electrode material. The results of the MIM parallel plate capacitor structure of Ag/BST/MoSi 2 /n-Si exhibited the highest capacitance density achievement of 405 nFcm − 2 with a dielectric loss of 0.048. An optimal recorded dielectric loss was 0.024 at 10 VDC for the device structure In/BST/MoSi 2 /n-Si. The MoSi 2 /BST/MoSi 2 /n-Si a full parallel-plate ceramic capacitor device structure had a capacitance density of 47 nFcm − 2 , a dielectric constant of 22.3; and a dielectric loss of 0.035.