US Patent 10049891 Selective in situ cobalt residue removal

Exemplary methods for removing cobalt material may include flowing a chlorine-containing precursor into a processing region of a semiconductor processing chamber. The methods may include forming a plasma of the chlorine-containing precursor to produce plasma effluents. The methods may also include contacting an exposed region of cobalt with the plasma effluents. The methods may include flowing a nitrogen-containing precursor into the processing region of the semiconductor processing chamber. The methods may further include contacting the cobalt chloride with the nitrogen-containing precursor. The methods may also include recessing the cobalt, which leaves a residue behind. The methods may include forming a remote plasma of a hydrogen-containing precursor. The methods may also include removing the cobalt residue using plasma effluents of the hydrogen-containing precursor.