Abstract: Method and apparatus for uniform direct radiant heating in a rapid thermal processing reactor where uniformity of temperature across the width and breadth of a semiconductor wafer is achieved by placement of a dome-shaped thermal insert in close proximity to a semiconductor wafer in process. Thermal energy is absorbed by the thermal insert from the semiconductor wafer at a high rate where the spacing between the thermal insert and semiconductor wafer is at a minimum and at a gradually reduced rate where the spacing between the thermal insert and semiconductor wafer is gradually increased. A guard ring is also incorporated to negate bottom side reflective thermal energy exposure.