dA highly selective dry-etch process for conductive metals (Au, Pt, and Cu) and magnetic metal (20% Fe-Ni) has been developed using a magnetron reactive-ion-etching system employing a CO/NH3/Xe chemistry. Etch selectivities of these metals to titanium are greater than 80: 1 for Au, 40: 1 for Pt, 30: 1 for Cu, and 15: 1 for permalloy (20% Fe-Ni) at the titanium-etch rate of 1.0 nm/min. The etching was conducted at room temperature. It was observed that the small addition of Xe to CO/NH3 etch gases (molar ratio= 1/7) increased the etch rate of these metals while promoting nitridation of the titanium mask and achieving enhanced selectivity. The titanium can be used both as a mask for the sputter etching of noble metals and as a mask for the reactive-ion etching of magnetic metals in the plasma. By about a factor of 3, the inclusion of Xe enhanced the etch selectivities for noble metals, copper, and a magnetic metal over titanium. (C) 2003 American Vacuum Society.