The growth kinetics of rf sputtered Ba2Si2TiO8 thin films

Radio‐frequency sputtered barium titanium silicate (BST), Ba2Si2TiO8, thin films were grown on crystalline Si(100) substrates at substrate temperatures ranging from 750 to 955 °C and were characterized using x‐ray diffraction, optical microscopy, and scanning electron microscopy. The result of x‐ray diffraction analysis indicates that the BST films deposited at an optimum substrate temperature of 845 °C were strongly c‐axis oriented. The corresponding film growth rate in the direction normal to the film surface and lateral grain growth rate were 1.95 nm/min and 0.77 μm/min, respectively, at the initial stage of deposition. The former decreased with sputtering time and the latter increased with grain size. The fast lateral grain growth rate indicates a strong interaction between the overgrown BST film and the Si substrate. The increase in lateral grain growth rate suggests a surface diffusion controlled nucleation and growth mechanism in the initial stage of the deposition, and a coalescence mechanism domi...