US Patent 6867086 Multi-step deposition and etch back gap fill process

High density plasma chemical vapor deposition and etch back processes that can fill high aspect ratio (typically at least 5:1, for example 6:1), narrow width (typically sub 0.13 micron, for example 0.1 micron or less) gaps with significantly reduced incidence of voids or weak spots are provided. This deposition part of the process may involve the use of any suitable high density plasma chemical vapor deposition (HDP CVD) chemistry. The etch back part of the process involves an integrated multi-step (for example, two-step) procedure including an anisotropic dry etch followed by an isotropic dry etch. The all dry deposition and etch back process in a single tool increases throughput and reduces handling of wafers resulting in more efficient and higher quality gap fill operations.