Sputter deposition method for improved bottom and side wall coverage of high aspect ratio features

摘要

A method of sputter deposition for improved side wall and bottom coverage of high aspect ratio features on a substrate includes alternatingly exposing the substrate having high aspect ratio features to a collimated sputtered particle flux and a less-collimated sputtered particle flux until a desired deposition thickness is reached. A confining magnetic field may be used to reduce electron losses at process chamber walls, allowing for improved collimation of the collimated flux. The substrate may also be heated or biased during exposure to the less-collimated flux to increase the good side wall and step coverage of the less-collimated flux, and cooled or reverse-biased during exposure to the collimated flux to increase the good bottom coverage of the collimated flux. Alternatively, the substrate may be exposed to only a collimated flux, but good sidewall coverage by be achieved by alternating the temperature and/or bias of the substrate to provide the desired side wall and step coverage.