Patent ID: 8314371
Filing Date: 2012-11-20
Classification: C23C,H01L

Abstract:
1. A rapid thermal processing apparatus for processing a planar substrate, the apparatus comprising: a chamber including a heat source; a first substrate support to hold the substrate in the chamber in a first position; a second substrate support in a second position to hold the substrate during thermal processing, the second substrate support being movable in a direction to place the substrate closer to and further from the heat source; a sensor to sense the position of the substrate relative to the second substrate support, the sensor comprising, a light source to direct light onto a surface of the substrate, an optical detector to monitor an intensity of light reflected from the surface of the substrate, and an electronic controller in communication with the optical detector, the electronic controller generating a plurality of measurements from reflections detected by the detector to calculate a location on the substrate surface where a reflection occurred, including determining which of the measurements corresponds to an edge of the substrate; and an actuator in communication with the sensor to change the position of the substrate relative to the axial position of the second substrate support.