Composite and multilayered TaO_x-TiO_y high dielectric constant thin films

A novel low temperature deposition process using reactive pulsed dc magnetron sputtering has been developed to deposit thin dielectric films composed of either a composite or alternating layers of tantalum oxide and titanium oxide. Capacitors fabricated from these dielectric materials have been found to exhibit exceptional electrical properties. For the composite material, one film containing 22% TiO_y had a high dielectric constant of 38, a leakage current density of 10^-6 A/cm² at 0.5 MV/cm, and a relatively high breakdown field strength of 2.3 MV/cm. By a slight modification of the deposition conditions, alternating layers of tantalum oxide and titanium oxide were deposited to form a high dielectric constant material. The electric at properties of these films were also exceptional: a dielectric constant of 44, a leakage current density of 3.4·10^-8 A/cm² at 0.5 MV/cm, and a breakdown field strength of 2.3 MV/cm. These films have potential applications in memory and advanced electronics packaging