Method and apparatus for physical confinement of a liquid meniscus over a semiconductor wafer

Abstract

Apparatus, methods and systems for physically confining a liquid medium applied over a semiconductor wafer include a first and a second chemical head that are disposed to cover at least a portion of a top and an underside surface of the semiconductor wafer. Each of the first and the second chemical heads include an angled inlet conduit at a leading edge of the respective chemical heads to deliver liquid chemistry into a pocket of meniscus in a single phase. The pocket of meniscus is defined over the portion of the top and underside surface of the semiconductor wafer covered by the chemical heads and is configured to receive and contain the liquid chemistry applied to the surface of the semiconductor wafer as a meniscus. A step is formed at a leading edge of the first and second chemical heads along an outer periphery of the pocket of meniscus to substantially confine the meniscus of the liquid chemistry within the pocket of meniscus. The step covers at least a portion of the pocket of meniscus and the step's height is sufficient to preserve confinement characteristic of the meniscus. An inner return conduit is defined within the pocket of meniscus at a trailing edge of the respective chemical heads and is used to remove the liquid chemistry from the surface of the semiconductor wafer in a single phase after the cleaning process.