The present disclosure generally relates to methods for processing of substrates, and more particularly relates to methods for forming a metal gapfill. In one implementation, the method includes forming a metal gapfill in an opening using a multi-step process. The multi-step process includes forming a first portion of the metal gapfill, performing a sputter process to form one or more layers on one or more side walls, and growing a second portion of the metal gapfill to fill the opening with the metal gapfill. The metal gapfill formed by the multi-step process is seamless, and the one or more layers formed on the one or more side walls seal any gaps or defects between the metal gapfill and the side walls. As a result, fluids utilized in subsequent processes do not diffuse through the metal gapfill.