Radiation-assisted selective deposition of metal-containing cap layers

Abstract

A method for integrating metal-containing cap layers into copper (Cu) metallization of semiconductor devices to improve electromigration and stress migration in bulk Cu metal. In one embodiment, the method includes providing a patterned substrate containing Cu metal surfaces and dielectric layer surfaces, exposing the patterned substrate to a process gas comprising a metal-containing precursor, and irradiating the patterned substrate with electromagnetic radiation, where selective metal-containing cap layer formation on the Cu metal surfaces is facilitated by the electromagnetic radiation. In some embodiments, the method further includes pre-treating the patterned substrate with additional electromagnetic radiation and optionally a cleaning gas prior to forming the metal-containing cap layer.