This Small Business Innovation Research (SBIR) Phase I project will extend the control of microelectronics manufacturing equipment systems down to room temperature. As a state-of-the-art method for performing several important steps in semiconductor fabrication, Rapid Thermal Processing (RTP) is the motivating application. At high temperatures (above 500oC), sensors (pyrometers) are available for temperature measurement, and good process models exist, so that feedback control can be used. At low temperatures (below 500oC) neither sensors nor models are available, so that feedback control is not possible. Phase I will develop a physically-based nonlinear model of the process, valid at both low and high temperatures, and an innovative non-contact temperature sensor will be modeled. These models will be combined, a baseline temperature controller will be synthesized, and a closed-loop system will be simulated to demonstrate control at low temperatures. In Phase II a prototype sensor would be built and tested in a commercial RTP chamber under closed-loop control. This approach promises to make significant improvements in throughput by allowing precise control over a broad range of temperatures. The new sensor and controller will be installed on an advanced commercial RTP chamber. Potential commercial applications are expected for a real-time sensor and controller product with accompanying embedded software.