It is even more important if you measure temperature at different points on the same wafer, on different wafers or in different reactors simultaneously or if you compare the temperature of different runs. Dr. Tony SpringThorpe of the National Research Council of Canada reported recently about fast and easy temperature calibration of all 3 heating zones of his showerhead reactor. Dr. SpringThorpe uses LayTec's AbsoluT for calibration of EpiTriple TT that monitors the growth of As- and P-based devices by 3 measurement heads at 3 different viewports. AbsoluT sets up one exact reference point for pyrometry measurements at 3 viewports, where temperature variations are often caused by adjustment, window coating or manufacturing tolerances of the equipment.
According to Dr. SpringThorpe, "AbsoluT is a quantum leap compared to the former calibration methods. It takes only 5 minutes to calibrate all 3 heads and requires no further calculation. Hence, I can take under real-time control all 3 heating zones. This helps enormously to grow uniform buffer and MQW structures. I am convinced that every MOCVD system should be equipped with AbsoluT."
