Abstract: Embodiments of the disclosure provided herein generally relate to a bottom cover plate (BCP) that enables control of radiation loss from a heating element inside a chamber for processing a substrate. The heating element is used to heat the substrate before or during processing and may heat the substrate unevenly due to uneven heat losses within the chamber. For example, the uneven heating of the substrate may result in uneven deposition of a material on the substrate, which may result in excess processing to correct the deposition or wasted product from disposing of improperly processed substrates. The BCP may be used to correct the uneven heating of the substrate.