Pressure-controlled two-step TEOS-O/sub 3/ CVD eliminating the base material effect

A new pressure-controlled two-step TEOS-O/sub 3/ CVD has been developed to provide high quality SiO/sub 2/ films with flow-like step-coverage regardless of the underlying materials. Thin films, initially deposited under a low pressure but high O/sub 3/ concentration prior to the deposition of main films under sub/atmospheric pressure (AP), have as high quality as AP-TEOS-O/sub 3/ films, and eliminate the base material effect. Gap-filling for 0.2-/spl mu/m spaces with a high aspect ratio of 3.1 has been achieved.