Method of fabricating a damascene copper inductor structure using a sub-0.18 um CMOS process

摘要

A process for integrating the fabrication of a thick, copper inductor structure, with the fabrication of narrow channel length CMOS devices, has been developed. The integrated process features the use of only one additional photolithographic masking step, used to form the opening in an IMD layer, that will accommodate the subsequent inductor structure. After forming damascene type openings in the same IMD layer, in the CMOS region, copper is deposited and then defined, to result in a thick, copper inductor structure, in the opening in the IMD layer, in a first region of a semiconductor substrate, as well as to result in copper interconnect structures, in the damascene type openings located in a second region of the semiconductor structure, used for the narrow channel length CMOS devices. The use of a thick, copper inductor structure, equal to the thickness of the IMD layer, results in increased inductance, or an increased quality factor, when compared to counterparts formed with thinner metal inductors.