A method for using ALD and RVD techniques in semiconductor manufacturing
to produce a smooth nanolaminate dielectric film, in particular for
filling structures with doped or undoped silica glass, uses dynamic
process conditions. A dynamic process using variable substrate (e.g.,
wafer) temperature, reactor pressure and/or reactant partial pressure, as
opposed to static process conditions through various cycles, can be used
to minimize film roughness and improve gap fill performance and film
properties via the elimination or reduction of seam occurrence. Overall
film roughness can be reduced by operating the initial growth cycle under
conditions which optimize film smoothness, and then switching to
conditions that will enhance conformality, gap fill and film properties
for the subsequent process cycles. Film deposition characteristics can be
changed by modulating one or more of a number of process parameters
including wafer temperature, reactor pressure, reactant partial pressure
and combinations of these.