Ferroelectric integrated circuit having low sensitivity to hydrogen exposure and method for fabricating same

摘要

A hydrogen barrier layer (128) is formed above a ferroelectric thin film (124) in an integrated circuit. The hydrogen barrier layer (128) is directly over a protected segment (123) of the ferroelectric thin film (124), while a sacrificial segment (125) of the ferroelectric thin film (124) extends laterally beyond the edges (129) of the hydrogen barrier layer (128). The sacrificial segment (125) absorbs hydrogen so that it cannot diffuse laterally into the protected segment (123) of the ferroelectric thin film (124). After it absorbs hydrogen, the sacrificial segment (125) is etched away to allow electrical connection to circuit layers below it. The ferroelectric thin film (124) preferably comprises a layered superlattice compound. Excess bismuth or niobium added to the standard precursor solution of a strontium bismuth tantalum niobate material helps to reduce hydrogen degradation of the ferroelectric properties.