Interconnect Fabrication by Superconformal Iodine-Catalyzed Chemical Vapor Deposition of Copper

Abstract

The mechanism behind superconformal filling of fine features during surfactant catalyzed chemical vapor deposition (CVD) is described and the metrology required to predict it is identified and quantified. The impact of adsorbed iodine coverage on copper deposition rate during chemical vapor deposition of copper on planar substrates is determined first. These kinetic parameters are then used in a model based on the curvature-enhanced accelerator coverage mechanism to predict superconformal filling during iodine-catalyzed CVD. In this model, the coverage of the adsorbed catalyst is presumed to change with surface area during interface evolution. The surface area decreases along the bottoms of submicrometer dimension features, increasing the local coverage and deposition rates and thereby enabling superconformal filling. Experimental filling results are then described and shown to be consistent with the predictions. © 2003 The Electrochemical Society. All rights reserved.