Controlled ion beam sputter deposition of W/Cu/W layered films for microelectronic applications

Abstract

Initial results are presented and discussed in relation to a research program focused on investigating the feasibility of using ion beamsputter deposition to produce layered films for metallization of microcircuits. An automated ion beam sputter‐deposition system has been used to produce W/Cu/W layered films and investigate their microstructural, morphological, and electrical characteristics. Layered films with smooth surfaces have been deposited on planar surfaces and in vias with reasonable conformality. It is demonstrated that the W layer microstructure can be tailored by controlling the deposition parameters. The control of the W layer microstructure can serve to improve its diffusion barrier properties with respect to similar films produced by other techniques. Initial measurements of the resistivity of the layered film structure yielded values close to that characteristic of bulk copper, a desirable parameter for application in microcircuitmetallization.