Rapid Thermal Processing (RTP)
Temperature Control & Thermal Modeling
SC Solutions provides embedded real-time controllers for Rapid Thermal Processing systems. Our model-based temperature controllers meet the extremely demanding performance specifications necessary for maximizing RTP wafer quality, such as fast ramp-rates, low overshoot, and tight temperature uniformity. The complex dynamic nature of the RTP process combined with very fast ramp rates (50-200°C/sec) make SC Solutions’ model-based controllers crucial for meeting the stringent requirements of RTP technology.
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Generic RTP reactor: axisymmetric geometry with five independent lamp rings, quartz window and showerhead, and silicon guard ring.
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SC Solutions’ Model-Based Controller Technology
The cornerstone of our technology is physical Model-Based Control System (MBCS) design. With this approach a physical model of the equipment (e.g., a thermal model of wafer temperature) is used directly in the control design. This provides a powerful "virtual" prototyping environment that can be used to evaluate closed-loop performance for either existing equipment or for next generation equipment that is still on the drawing board.
Physical Modeling
SC Solutions uses proprietary modeling software to develop high-fidelity thermal models that provide valuable design and performance information about the system. At the same time, the models can be specifically tailored for the development of controllers. SC Solutions’ modeling tools are capable of accurately characterizing complex surface-to-surface radiation transfer, including directional and spectral radiative properties. This capability also makes it possible to accurately model pyrometer temperature sensors, a crucial part of the overall system performance. The resulting models have been validated on commercially available RTP systems and found to be very accurate.
Control Design
SC Solutions designs high performance controllers using advanced robust multivariable control design techniques and the non-linear physical models described above. A major advantage of this approach is that the effects of chamber design modifications, wafer property variations, etc., can be evaluated in simulation for their influence on ultimate process uniformity. In addition, the closed-loop simulation can be used to help diagnose customer performance problems.
Implementation
SC Solutions uses state-of-the-art automatic code generation tools to produce source code that implements the controller algorithm, thus eliminating coding errors usually associated with software development. The resulting code can be rapidly (re)targeted to a wide range of hardware platforms, or can be delivered as a turn-key hardware system with custom hardware, software, and user interfaces.
