MODEL BASED LAMP BACKGROUND FILTRATION OF STRAY RADIATION FOR PYROMETRY

摘要

The embodiments described herein generally relate to methods of noise compensation for proper temperature detection in thermal processing chambers and devices for achieving the same. Methods can include determining noise produced by a lamp zone and extrapolating the noise from the detected photocurrent. Devices can include a processing chamber, a substrate support disposed in the processing chamber, the substrate support having a high thermal mass, a pyrometer below the substrate support and oriented to view radiation emitted by the substrate and a controller configured to subtract a time invariant noise component and a time variant noise component from the pyrometer signal.

主权项

1. A method of noise correction comprising:
measuring lamp noise detected by a pyrometer in a process chamber at a temperature near ambient temperature, the process chamber comprising one or more pyrometers and one or more lamp zones, the lamp noise measuring comprising:
measuring a first photocurrent at a first pyrometer of the one or more pyrometers;supplying a first voltage to a first lamp zone of the one or more lamp zones;maintaining the first voltage for a first period of time, wherein a second photocurrent is measured by the first pyrometer during the first period of time;supplying a second voltage which is greater than the first voltage to the first lamp zone;maintaining the second voltage for a second period of time, wherein the second period of time is less than the first period of time, and wherein a third photocurrent is measured by the first pyrometer during the second period of time;repeating the supplying the first voltage, the maintaining the first voltage, the supplying the second voltage and the maintaining the second voltage one or more times to collect a plurality of first order time-response values; andaveraging at least a portion of the first order time-response values to create a steady state value for each of the first order time response values.