Hints, Tips and Solutions

Q. How do I Simulate Rapid Thermal Annealing Temperature Transients in Vacuum?

A. When a wafer is clamped only at its edges and is heated with an infra-red source in a vacuum, the majority of the heat loss occurs through black body radiation. The vacuum prevents thermal conduction mechanisms for the majority of the wafer area. It is also important to realize that if both sides of the wafer are exposed to the vacuum without contact to a conductive heat sink, both the front and back sides of the wafer will radiate heat and so black body heat radiation must be simulated from both surfaces for accurate results.

In Atlas, black body radiation is simulated with an additional logical parameter, “BLACKBODY” added to the “THERMCONTACT” statement. This allows the user to set up multiple thermally radiative boundary conditions in their structure.