Physical and Electrical Properties of Thin-Film Barium Titanate Prepared by RF Sputtering on Silicon Substrates

Thin films of barium titanate in the range of 0.2 to 1.25 microns were successfully grown by RF sputtering on doped silicon substrates with resistivities of 0.002 cm to 0.25 cm . Two types of film crystal structures were achieved: 1)mixed orientation growth; and 2) preferred orientation growth along the < 100 > axis. The film stoichiometry was very much dependent on film structure during deposition. The effective crystallite size and nonuniform strain were also found to depend on the initial growth conditions. The electrical properties of these films were strongly influenced by the initial growth conditions and physical structure. The following are some of the important electrical properties: relative dielectric constant-110 to 215; loss factor-l.8 to 5.0 percent; electrical resistivity-lO¹⁰to 10¹³ cm; and dielectric breakdown->lO⁵V/cm.