INVESTIGATION OF THE WAFER TEMPERATURE UNIFORMITY IN AN OMVPE VERTICAL ROTATING-DISK REACTOR

Measuring the wafer temperature uniformity is one of most difficult pr oblems in the development of organometallic vapor phase epitaxy (OMVPE ) equipment. Until recently, the lack of a good experimental technique limited the understanding of OMVPE rotating disk reactor (RDR) therma l dynamic. We have developed a rotating wafer thermal imaging techniqu e, which for the first time allows a real-time experimental investigat ion of the temperature distribution across the wafer in an RDR under r ealistic deposition conditions. This technique allows investigation on how process parameters such as the growth temperature (from 650 to 80 0 degrees C), reactor pressure (from 10 to 620 Torr), reactant flow (f rom 2 to 30 slm), and wafer carrier rotation speed (from 300 to 1030 r pm) affect the wafer temperature uniformity. This information has allo wed us to establish under which conditions single or multi-zone heatin g should be used in the OMVPE reactor. A wafer temperature uniformity of better than 1 degrees C was demonstrated for both an optimized sing le zone heating system under a selected combination of process paramet ers, and for a two-zone heating system over a wide range of the proces s parameters.