DESIGN CONSIDERATIONS FOR THE ELIMINATION OF RECIRCULATION IN HORIZONTAL EPITAXIAL REACTORS

The phenomenon of recirculation in horizontal epitaxial reactors has been studied using a computer model, which includes a rigorous calculation of the radiative heating of the reactor wall using the enclosure theory of radiation, in conjunction with a two-band absorption model for quartz. Alternative ways of eliminating recirculation are presented and evaluated. These include reducing the reactor pressure, increasing the gas flow rate, reducing the reactor height and changing the susceptor slope. Two Figures of Merit, based on high efficiency of growth and large area growth uniformity, have been defined and used to compare the relative advantages and disadvantages as well as tradeoffs between these alternatives. Reactor wall temperatures have also been considered while comparing these alternatives. Reducing the reactor height with an optimum susceptor slope is shown to be the best way of eliminating recirculation, based on these criteria.