Rf-Sputtered Tetragonal Barium Titanate Films on Silicon

摘要

Tetragonal crystals of BaTiO sub 3 with ferroelectric properties are regularly observed for BaTiO sub 3 films thicker than 1000 A rf sputter deposited at 5 A/min onto silicon substrates at temperatures above 500 exp 0 C. There is a severe interaction problem between the silicon substrate and the BaTiO sub 3 that contaminates the film, which can be avoided by growing a pacification layer of SiO sub 2 on the silicon substrate before depositing BaTiO sub 3 . Despite a coefficient of thermal expansion mismatch between BaTiO sub 3 and silicon, thin films with good electrical insulation properties can be obtained when the substrate temperature exceeds 300 exp 0 C by reducing the substrate temperature during the deposition by 6.5 to 7.0 exp 0 C/min to a final substrate temperature of 200 exp 0 C. (ERA citation 04:001113)