Dielectric films for capacitor applications in electronic technology

In microelectronic applications, various approaches have been used to provide high capacitance thin film components. None of these has been widely accepted for reasons that are both technical and economic. Limited applications have been made of silicon and other simple oxides, e.g., of aluminum or tantalum, as dielectric media. Particularly in the area of microwave integrated circuits, requirements for high frequency, high specific capacitance, low to moderate loss, and integrability call for new thin film approaches. These requirements will only be met by using more complex compounds, possibly of ferroelectric materials. Aspects of material preparation, composition evaluation, and dielectric performance of thin film bismuth titanates are treated in a manner which should be of value in considering other complex dielectrics for similar use. Of particular technological importance is the use of thin silica barrier layers at the metal electrodes to permit achieving low dielectric loss.