Response Surface Technique for Ex Situ Process Uniformity Optimization in a Multi-Zone RTP System

Abstract

AbstractMany RTP reactors used in production presently employ single point temperature measurement along with multiple lamp zone control. Optimum zone settings in these systems are known to vary depending on the radiative properties of the wafer and the process. Therefore, tuning the system to meet specifications for a new process is achieved by an operator analyzing metrology results and drawing on experience with the system to determine proper zone settings. It would be desirable to have a technique which can be used to optimize the lamp zone settings in an automatic manner that would be the same for every user. Furthermore, such a technique should be both simple to use and robust. In this work a method is presented which relies on an empirical response surface and an interative computational technique to minimize process variance. The results show that the method works regardless of the process variable being optimized, i.e. temperature, oxide thickness, etc., and that the method relies on no user input.