The invention enables a layer of metal to be formed on a substrate with few
or no voids formed in the layer, with increased throughput and without
raising the temperature of the substrate to a level that may damage the
substrate. A layer of metal can be formed on a substrate using a cold
deposition step followed by a hot deposition step. The cold deposition
step need only be performed for a time sufficient to deposit metal over
the entire surface on which the metal layer is to be formed. In the hot
deposition step, further metal is deposited while the substrate is rapidly
heated to a target temperature. The rapid heating quickly mobilizes the
atoms of the deposited metal, making the deposited metal far less
susceptible to cusping and voiding than has been the case with previous
methods for depositing a metal layer on a substrate that include a cold
deposition step followed by a hot deposition step. In particular, the
rapid heating of the substrate can be accomplished by, for example,
flowing a heated gas against the substrate at a flow rate that is higher
than heretofore thought feasible.