Support plate for localized heating in thermal processing systems
Support plates for localized heating in thermal processing systems to uniformly heat workpieces are provided. In one example implementation, localized heating is achieved by modifying a heat transmittance of a support plate such that one or more portions of the support plate proximate the areas that cause cold spots transmit more heat than the rest of the support plate. For example, the one or more portions (e.g., areas proximate to one or more support pins) of the support plate have a higher heat transmittance (e.g., a higher optical transmission) than the rest of the support plate. In another example implementation, localized heating is achieved by heating a workpiece via a coherent light source through a transmissive support structure (e.g., one or more support pins, or a ring support) in addition to heating the workpiece globally by light from heat sources.
1. A support plate for supporting a workpiece in a thermal processing apparatus, the support plate comprising:
a base;
at least one support structure extending from the base, the at least one support structure configured to support the workpiece during thermal processing, the at least one support structure comprises a plurality of support pins;
wherein the base comprises a first portion associated with a first heat transmittance and a second portion associated with a second heat transmittance, the second heat transmittance being higher than the first heat transmittance, wherein the second portion is located proximate to the at least one support structure, the second portion comprises a plurality of circular areas located where the plurality of support pins contact the base, each circular area having a center in the second portion that coincides with a center of a respective support pin of the plurality of support pins, a diameter of each circular area is greater than a diameter of each respective support pin, wherein the first portion is the remaining area of the base excluding the second portion.
2. The support plate of claim 1 , wherein the second portion comprises untreated quartz, and the first portion comprises treated quartz, wherein the treated quartz has reduced optical transmittance relative to the second portion.
3. The support plate of claim 2 , wherein the treated quartz is treated with one or more of grinding, coating, engraving, or doping.