Method for fabricating ferroelectric integrated circuits including a hydrogen heating step

摘要

An integrated circuit is formed that contains a ferroelectric element (122) comprising metal oxide material containing at least two metals. Various methods and structures are applied to minimize the degradation of ferroelectric properties caused by hydrogen during fabrication of the circuit. Oxygen is added to some elements of the integrated circuit to serve as a getter of hydrogen during fabrication steps. To minimize hydrogen degradation, the ferroelectric compound can be fabricated from a liquid precursor containing one or more of the constituent metals in excess of the amount corresponding to a stoichiometrically balanced concentration. A hydrogen barrier layer (126), preferably comprising titanium nitride, is formed to cover the top of the ferroelectric element (122). A hydrogen heat treatment in hydrogen gas is performed on the integrated circuit at a temperature from 200° to 350°C and for a time period not exceeding 30 minutes to minimize degradation of the ferroelectric properties by hydrogen while restoring other properties of the integrated circuit. An oxygen recovery anneal at 800°C after high-energy hydrogen steps restores ferroelectric properties.