Distributed Temperature Controllers

SC Solutions provides solutions for distributed temperature control. Our model-based temperature controllers meet the extremely demanding performance specifications set by the semiconductor and advanced materials processing industries, such as fast ramp-rates, negligible overshoot, and tight temperature uniformity. We provide temperature control and thermal modeling solutions for a wide range of systems, including single-wafer and batch-wafer furnace systems for the semiconductor industry, and advanced materials deposition systems.

To achieve the best possible performance, we tune the controller to your system using physical model-based control system design. With this approach a physical model of the equipment (e.g., a  fluid-thermal model that predicts wafer temperature) is used directly in the control design. The thermal model accurately captures input-output behavior, and can also monitor the performance of unmeasured process variables (temperatures) of interest. This approach provides a powerful "virtual" prototyping environment that is used to evaluate closed-loop performance for either existing equipment, or for evaluating and optimizing equipment re-design prior to any expensive hardware modifications.

Modeling

SC Solutions uses proprietary modeling software to develop high-fidelity thermal models that provide valuable design and performance information about the system. SC Solutions' modeling tools accurately characterize complex surface-to-surface radiative heat transfer, including directional and spectral radiative properties. This capability also makes it possible to accurately model temperature sensors (e.g., pyrometers), a crucial part of overall system performance. The resulting models have been validated on commercial systems and found to be very accurate. These models provide a reliable basis for optimal feedback and/or feedforward control design.

Control Design

SC Solutions designs high performance controllers using advanced robust multivariable control design techniques based on non-linear physical models. 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. Once the performance meets (or exceeds) specification, the feedback controller is used to control the actual system. This approach not only provides physical insight into the open-loop and closed-loop behavior of the system but can also be used to extract maximum performance from the thermal processing system.

Example Application

SC Solutions’ high-performance temperature controllers are widely used in commercial RTP (Rapid Thermal Processing) systems. Here,  the multiple sensors and actuators, combined with very fast ramp rates (50-200°C/sec), constitute a complex, non-linear, tightly-coupled, dynamic system. These features of the RTP process make SC Solutions' multivariable model-based controllers crucial for meeting the stringent requirements of this technology.

Implementation

SC Solutions uses state-of-the-art automatic code generation tools to produce source code that implements the controller algorithm.  This process significantly reduces sources of coding errors associated with software development, and decreases development time. The resulting code is targeted to your desired hardware platform using our SCx™ Real Time Controller Software Framework, or can be delivered as a turn-key system with custom hardware and software that meets your measurement, actuation, data-logging and user interface needs.