Embodiments of the invention relate generally to an ultraviolet (UV) cure chamber for curing a dielectric material disposed on a substrate and to methods of curing dielectric materials using UV radiation. A substrate processing tool according to one embodiment comprises a body defining a substrate processing region; a substrate support adapted to support a substrate within the substrate processing region; an ultraviolet radiation lamp spaced apart from the substrate support, the lamp configured to transmit ultraviolet radiation to a substrate positioned on the substrate support; and a motor operatively coupled to rotate at least one of the ultraviolet radiation lamp or substrate support at least 180 degrees relative to each other. The substrate processing tool may further comprise one or more reflectors adapted to generate a flood pattern of ultraviolet radiation over the substrate that has complementary high and low intensity areas which combine to generate a substantially uniform irradiance pattern if rotated. Other embodiments are also disclosed.