Thin film capacitor element

摘要

A thin film capacitor is provided with a thin film protection element to protect the capacitor from damage that can result due to the occurrence of an electrostatic discharge event. The thin film capacitor includes two conductive film portions forming capacitor plates and a dielectric film forming the capacitor dielectric. The protection element may take the form of a thin film diode or a series of thin film diodes connected electrically in parallel with the thin film capacitor. The whole device can be fabricated using a stoichiometric silicon nitride layer to produce the capacitor dielectric and a non-stoichiometric silicon rich silicon nitride layer to provide the diode semiconductor material. One diode is formed by one capacitor plate, the semiconductor layer and an upper diode contact. In an alternative construction the protection element takes the form of a narrow gap defined by one conductive film portion electrically connected to one capacitor plate and another conductive film portion electrically connected to the other capacitor plate. During an electrostatic discharge event charge is able to cross the narrow gap rather than pass through the capacitor dielectric material.