The present invention is directed to a semiconductor thermal processing system and an apparatus for thermally cooling a semiconductor substrate. According to one aspect of the present invention, a semiconductor thermal processing system and associated apparatus and method are disclosed which provides a segmented cold plate situated within a process chamber, wherein a plurality of segments of the cold plate are operable to radially translate between an engaged position and a disengaged position, wherein a substrate holder may pass between the plurality of segments when the segments are in the disengaged position. According to another aspect, an elevator is operable to linearly translate a substrate residing on a substrate holder between a heating position proximate to a heater assembly and a cooling position proximate to the segmented cold plate. According to another aspect, the cold plate comprises a plurality of holes through which one or more gases may flow, wherein an amount or mixture of the one or more gases is controllable via a controller, and wherein one or more temperature sensors are operable to provide temperature feedback at the substrate. According to another aspect the substrate resides within close proximity to the cold plate, wherein when gas is flowed through the holes, the substrate is cooled in the viscous regime, and the amount and / or mixture of gases flowed through the holes is controlled, based, at least in part, on the one or more measured temperatures.