1. An apparatus for processing wafer-shaped articles, comprising:a closed process chamber;
a spin chuck for holding a wafer-shaped article in a predetermined orientation, said spin chuck including a plurality of downwardly-depending gripping pins arranged in a circular series and disposed within the closed process chamber,
a rotating shower head included within an upper dispense unit for supplying process gas to a first surface of a wafer-shaped article when held by said plurality of downwardly-depending gripping pins, said rotating shower head comprising an outlet plate having a plurality of openings formed in each of a central and a peripheral region thereof,
a process gas feed for supplying process gas to a gas distribution chamber defined within the closed process chamber, said gas distribution chamber being in fluid communication with said plurality of openings formed in said rotating shower head, and
a blocking gas feed for supplying blocking gas to a gap defined between an inner surface of said closed process chamber and an outer periphery of said spin chuck to confine process gas within said gas distribution chamber,
wherein each of said plurality of downwardly-depending gripping pins is configured to retain said wafer-shaped article such that a second surface of said wafer-shaped article is oriented with respect to a lower dispense unit.