SEMICONDUCTOR DEVICES INCLUDING BULB-SHAPED TRENCHES

摘要

A method of creating a trench having a portion of a bulb-shaped cross-section in silicon is disclosed. The method comprises forming at least one trench in silicon and forming a liner in the at least one trench. The liner is removed from a bottom surface of the at least one trench to expose the underlying silicon. A portion of the underlying exposed silicon is removed to form a cavity in the silicon. At least one removal cycle is conducted to remove exposed silicon in the cavity to form a bulb-shaped cross-sectional profile, with each removal cycle comprising subjecting the silicon in the cavity to ozonated water to oxidize the silicon and subjecting the oxidized silicon to a hydrogen fluoride solution to remove the oxidized silicon. A semiconductor device structure comprising the at least one trench comprising a cavity with a bulb-shaped cross-sectional profile is also disclosed.

主权项

1. A semiconductor device structure, comprising:
trenches in silicon, wherein each trench of the trenches has an average width of from about 20 nm to about 60 nm; a liner on sidewalls of the trenches; and a cavity having a bulb-shaped cross-sectional profile at proximal portions of each trench of the trenches.