Performance optimization

Control variables for performance optimization include heater temperatures (powers), baseplate cooling, and reactor pressure.

A typical performance objective is to bring the wafers close to a desired temperature, while keeping wafer-to-wafer and across-wafer temperatures within prescribed limits to avoid `cracking' of wafers and achieve uniformity of wafers.

The above picture is the result of an optimization run with the goal to compute heater powers to achieve a uniform temperature distribution of 1027 C on the wafers during steady-state operation. The picture on the left shows the resulting temperatures in the middle of the wafers for the non-optimal, uniform power distribution (solid line) and the optimized power distribution (dashed line). The picture on the right shows the resulting temperature distributions inside the furnace. The percentages on the right indicate the differences between the optimized power distributions and the uniform power settings. (Full size picture)