GAPFILL IMPROVEMENT WITH LOW ETCH RATE DIELECTRIC LINERS

摘要

A method of filling a trench is described and includes depositing a dielectric liner with a high ratio of silicon oxide to dielectric liner etch rate in fluorine-containing etch chemistries. Silicon oxide is deposited within the trench and etched to reopen or widen a gap near the top of the trench. The dielectric liner protects the underlying substrate during the etch process so the gap can be made wider. Silicon oxide is deposited within the trench again to substantially fill the trench.