US 6,207,465 B1 · Method of fabricating ferroelectric integrated circuit using dry and wet etching

Abstract

In a ferroelectric integrated circuit, a hydrogen barrier layer comprising titanium or titanium nitride or both is formed over a metal oxide element to protect it from hydrogen degradation. After hydrogen annealing and other process steps causing hydrogenating or reducing conditions, the hydrogen barrier layer is removed in a two-step etching process. The first etch step is a dry etch, preferably a standard ion-mill etching process, which rapidly removes most of the hydrogen barrier layer. The second step is a wet, chemical etch, preferably using a solution containing NH4OH, H2O2, and H2O, which selectively removes remnants of the hydrogen barrier layer from the circuit by oxidizing a chemical element of the barrier layer. The metal oxide material preferably comprises a layered superlattice compound.

Claims24

Dependent claims

A method for fabricating ferroelectric integrated circuits comprising the steps of:

providing a substrate;
forming on said substrate a thin film of a ferroelectric metal oxide material;
forming a hydrogen barrier layer directly over at least a portion of said thin film of metal oxide material;
performing a dry etch to remove a significant portion of said hydrogen barrier layer;
and
performing a wet, chemical etch to remove remnants of said hydrogen barrier layer, said etch being stopped on a material selected from the group consisting of conductors and a ferroelectric material.

3 more elements

Dependencies are inferred from the claim text.

Method of fabricating ferroelectric integrated circuit using dry and wet etching

Life of this patent

Method of fabricating ferroelectric integrated circuit using dry and wet etching

Life of this patent

Abstract

Claims24