Microwave dielectric properties of the BaTi5O11 thin film grown on the poly-Si substrate using rf magnetron sputtering

BaTi5O11 thin films were grown on the poly-Si/SiO2/Si substrate using rf magnetron sputtering. The BaO-TiO2 thin film deposited on the poly-Si substrate had an amorphous phase even though the growth temperature was high at 550 degrees C. The amorphous film was crystallized into the BaTi5O11 phase when the film was post annealed above 800 degrees C. The post annealing temperature is one of the most important factors for the formation of the crystalline BaTi5O11 thin film. The homogeneous BaTi5O11 thin film was obtained when the film was grown at 550 degrees C and rapid thermal annealed (RTA) at 900 degrees C for 3 min. The dielectric constant (80 of the BaTi5O11 film measured at 100 kHz was about 35 and the dissipation factors of all the films were smaller than 4.0%. The dielectric properties of the BaTi5O11 thin film were also measured at microwave frequencies. For the BaTi5O11 thin film grown at 550 degrees C and RTA at 900 degrees C for 3 min, the epsilon(r) of 34-30 and dielectric loss of 0.025 +/- 0.005 were obtained at 1-6 GHz. (c) 2005 Elsevier Ltd. All rights reserved.