An oxide-nitride-oxide capacitor dielectric film for silicon strip detectors

Silicon strip detectors with integrated coupling capacitors were fabricated on the same wafer with capacitor test structures and dielectric breakdown characteristics were evaluated. The standard silicon dioxide (oxide) dielectric was compared to a stacked film of silicon dioxide-silicon nitride-silicon dioxide (ONO). The thicknesses for the stacked film were chosen to give approximately the same value of capacitance per unit area as for the oxide. Since the dielectric constant of silicon nitride is approximately twice that of silicon dioxide, the ONO film can be made thicker than the corresponding oxide for the same capacitance. As a result the ONO film has a significantly higher breakdown voltage than that of an oxide film with equivalent capacitance