Calibration wafer and method of calibrating in situ temperatures

A system for calibrating a temperature measurement device, comprising:

• a calibration target including a target material defining a first surface including a first region and a second region;
• a layer of a metal overlying said first region of said first surface and contiguous with said target material, said metal having higher reflectivity than said target material, said metal being adapted to form a molten eutectic phase with said target material in said first region at a known temperature and change reflectivity upon formation of said molten eutectic phase, said second region being devoid of said metal;
• an emitter adapted to direct radiant energy onto said first region so that said radiant energy will be reflected by said first region;
• a sensor unit including one or more sensors, said sensor unit being adapted to detect radiant energy reflected by said first region to obtain reflectivity data representing the reflectivity of said first region, said sensor unit also being adapted to detect radiant energy emitted by said second region to obtain temperature data representing the temperature of said target;
• and,
• a circuit electrically coupled to said sensor unit for monitoring said reflectivity data and said temperature data to determine the temperature represented by said temperature data when said change in reflectivity occurs.

A system for calibrating a temperature measurement device, comprising:

• a calibration target including a target material defining a first surface including a first region and a second region;
• a layer of a metal overlying said first region of said first surface and contiguous with said boundary of said second region, said metal having higher reflectivity than said target material, said metal being adapted to form a melt phase with said target material in said first region at a known temperature and change reflectivity upon formation of said melt phase, said second region being devoid of said metal;
• an emitter adapted to direct radiant energy onto said first region so that the direct radiant energy will be reflected by said first region;
• a sensor unit including one or more sensors, said sensor unit being adapted to detect radiant energy reflected by said first region to obtain reflectivity data representing the reflectivity of said first region, said sensor unit also being adapted to detect radiant energy emitted by said second region to obtain temperature data representing the temperature of said target;
• and,
• a circuit electrically coupled to said sensor unit for monitoring said reflectivity data and said temperature data to determine the temperature represented by said temperature data when said change in reflectivity occurs;
• wherein said sensor unit includes a pyrometer sensor having a field of view, the system further comprising a reaction chamber, a wafer carrier disposed in said reaction chamber, and a drive mechanism connected to said wafer carrier for moving said wafer carrier, said target being carried on said wafer carrier, said field of view being disposed in said reaction chamber so that said first and second regions of said surface will repeatedly pass through said field of view when said wafer carrier is moved by said drive mechanism;
• and
• wherein said drive mechanism is operative to rotate said wafer carrier about an axis and said target is mounted to said wafer carrier remote from said axis.

A system for calibrating a temperature measurement device, comprising:

• a calibration target including a target material defining a first surface including a first region and a second region;
• a layer of a metal overlying said first region of said first surface and contiguous with said target material, said metal having higher reflectivity than said target material, said metal being adapted to form a melt phase with said target material in said first region at a known temperature and change reflectivity upon formation of said melt phase, said second region being devoid of said metal;
• an emitter adapted to direct radiant energy onto said first surface so that said radiant energy will be reflected by said first surface;
• a sensor unit including one or more sensors, said sensor unit being adapted to detect radiant energy reflected by said first and second regions to obtain reflectivity data representing the reflectivity of said first and second regions, said sensor unit also being adapted to detect radiant energy emitted by said first and second regions to obtain temperature data representing the temperature of said target;
• and,
• a circuit electrically coupled to said sensor unit for monitoring said reflectivity data and said temperature data, said circuit being configured to compare said reflectivity data from said first region with said reflectivity data from said second region, whereby an accurate temperature represented by said temperature data may be determined when said reflectivity of said first region changes relative to said reflectivity of said second region.