Abstract: Methods for selectively etching titanium and titanium nitride are disclosed. In some embodiments the method involve exposing a workpiece to a first solution to remove titanium nitride, exposing the workpiece to a second solution to remove titanium, and exposing the workpiece to a third solution to remove residual titanium nitride, if any. The solutions are formulated such that they may selectively remove titanium and/or titanium nitride, while not etching or not substantially etching certain other materials such as dielectric materials, oxides, and metals other than titanium.

Abstract: An etching solution for a metal hard mask. The etching solution comprises a mixture of a dilute HF (hydrofluoric acid) and a silicon containing precursor. The etching solution also comprises a surfactant agent, a carboxylic acid, and a copper corrosion inhibitor. The etching solution is selectively toward etching the metal hard mask material (e.g., Titanium) while suppressing Tungsten, Copper, oxide dielectric material, and carbon doped oxide.

Abstract: An etching solution for a metal hard mask. The etching solution comprises a mixture of a dilute HF (hydrofluoric acid) and a silicon containing precursor. The etching solution also comprises a surfactant agent, a carboxylic acid, and a copper corrosion inhibitor. The etching solution is selectively toward etching the metal hard mask material (e.g., Titanium) while suppressing Tungsten, Copper, oxide dielectric material, and carbon doped oxide.

Abstract: An etching solution for a metal hard mask. The etching solution comprises a mixture of a dilute HF (hydrofluoric acid) and a silicon containing precursor. The etching solution also comprises a surfactant agent, a carboxylic acid, and a copper corrosion inhibitor. The etching solution is selectively toward etching the metal hard mask material (e.g., Titanium) while suppressing Tungsten, Copper, oxide dielectric material, and carbon doped oxide.