NOVELTY - The method involves performing an annealing process on a substrate (200) in a rapid thermal process chamber (300) having a substrate support ring (334) to support the substrate and a reflector plate (302) arranged proximate a back side of the substrate. Oxygen containing or nitrogen containing gas is provided to the back side via through-holes (327) in the plate. The chamber is maintained at pressures proximate to top and bottom surfaces of the substrate, respectively. One pressure is greater than the other pressure to prevent dislodgement of the substrate from the ring during processing.    USE - Method for processing a substrate of a semiconductor device. Uses include but are not limited to a doped or un-doped silicon substrate, III-V compound substrate, silicon germanium substrate, epi-substrate, silicon-on-insulator substrate and display substrate used in LCD, plasma display, electro luminescence lamp display, LED substrate, solar cell array and solar panel.    ADVANTAGE - The oxygen containing gas or nitrogen containing gas is provided to the back side via the through-holes in the reflector plate to facilitate control over ambient conditions proximate the back side of the substrate for reducing sublimation of materials or diffusion of dopants from the substrate, thus reducing or preventing deposition of materials on surfaces of the process chamber, and hence increasing production time before maintenance is necessary to clean the process chamber, and increasing process efficiency.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a INDEPENDENT CLAIMS are also included for the following:    (1) a computer readable medium having instructions to execute a method for processing a substrate    (2) an apparatus for processing a substrate.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic side sectional view of a process chamber.    Substrate (200)    Rapid thermal process chamber (300)    Reflector plate (302)    Through-holes (327)    Substrate support ring (334)