High-Performance Wafer Handling Systems for Semiconductor Automation

Nowadays, the overall productivity of the semiconductor FABs is becoming more and more dependent on the performance of the robotic systems, responsible for material handling within the front-end and back-end mini-environments. Regardless of how long particular processes take, the time for exchanging an already processed wafer, with an unprocessed one, is always becoming a bottleneck in the urge to increase the performance of the processing machines. To comply with the increased performance demands, while maintaining high accuracy and reliability requirements, the wafer handling robots have to be driven faster within the mechanical constraints imposed by the processing machines, as the cost and the size of the manipulated object significantly increases. The directions in which the manufacturers of wafer handling equipment concentrate their efforts are the design of mechanical systems with improved manipulating capabilities, direct-drive actuation, implementation of advanced control schemes, and last but not least optimal application of the wafer handling equipment through careful analysis of the manipulating task via elaborate case studies, mathematical modeling, simulation and on-site experiments. This article aims at addressing some of the approaches to increasing the performance capabilities of the robotic wafer handling system from both, a mechanical and a control point of view.