Lam Research Corporation
NUCLEATION-FREE TUNGSTEN DEPOSITION

Abstract:

Provided herein are methods of depositing tungsten (W) films without depositing a nucleation layer. In certain embodiments, the methods involve depositing a conformal reducing agent layer of boron (B) and/or silicon (Si) on a substrate. The substrate generally includes a feature to be filled with tungsten with the reducing agent layer conformal to the topography of the substrate including the feature. The reducing agent layer is then exposed to a fluorine-containing tungsten precursor, which is reduced by the reducing agent layer to form a layer of elemental tungsten. The conformal reducing agent layer is converted to a conformal tungsten layer.