Multivariable Feedback Control of Semiconductor Wafer Temperature
S. Norman and S. Boyd
Proceedings of the American Control Conference, 1:811-816, June 1992.
The authors consider the problem of wafer temperature control in rapid thermal processing (RTP) of semiconductor wafers. They present a novel approach to the analysis of candidate sensor configurations for multiactuator multisensor feedback control systems needed to ensure small temperature error in the face of substantial disturbances. The method allows minimization of worst-case temperature error in response to disturbances described by a realistic model. An example RTP system was analyzed. Results obtained with the example suggest that when feedback control of temperature error is implemented, overall system performance will depend critically on the sensor configuration.