Sensorization in a photolithography coat process

The growth of automation and automatic data collection in the semiconductor industry is providing engineers and manufacturers with an unprecedented insight into their processes and is crucial in the trend toward higher quality and error free processing. Some of the immediate benefits of automation are real time monitoring of process conditions, reduction in equipment downtime due to qualification testing, real time Statistical Process Control (SPC), elimination of operator induced error in equipment measurements, and process risk reduction. These benefits and others were realized through the implementation of a real time temperature monitoring system on a photolithography coat track. The system provides full time temperature monitoring, automatic SPC data logging during actual process conditions, state driven control of track interlock to prevent out of limit processing and process data tracking for real time performance of wafer bake stations. The system was realized by implementing a C-based state logic program in the QNX Windows real time operating system to drive Keithley METRABUS hardware monitoring SVG 8600 coat tracks.