Electrical Properties of Thin‐Film Capacitors of the Dy2O3‐B2O3‐SiO2 System

Thin dielectric films formed by evaporating a Dy2O3‐SiO2‐B2O3 mixture of a weight ratio of 80:10:10 exhibit excellent electrical, atmospheric, and mechanical stability in the temperature range from room ambient to 500°C. The mixture can be readily deposited from tantalum boats. The dielectric constant is about 4.5 and the dissipation factor varies from 0.003 to 0.006 at room temperature with a breakdown field strength of 4.0×106V/cm. The change in capacitance is about 5% at 470°C and about 20% at 500°C. The dissipation factor changes from 0.003 to 0.20 in the same temperature range. The film does not fracture or exhibit mechanical deformation at 500°C.