METHOD TO CALCULATE SUBSTRATE-TEMPERATURE DURING INTERMITTENT RADIANTHEATING IN VACUUM

We have developed a method to determine the time dependent temperature of intermittently radiation-heated substrates for epitaxial growth of Si in ultrahigh vacuum. The method is particularly useful during the time intervals of growth when a pyrometer cannot be relied on, e.g., d ue to light reflection from the substrate surface. The use of a thermo couple is not possible due to slow response and risk for contamination . The model has been derived by applying Stefan-Boltzmann's law and th e fact that heat radiation is the dominating energy transport mechanis m in the studied system for the actual substrate temperatures and time constants. The vertical temperature gradient through the substrate wa s estimated to be at most of the order of 100 K m-1.