Optimized Airborne Molecular Contamination Monitoring for Lithography

A new approach to monitoring airborne molecular contamination in lithography is presented by industry experts from Particle Measuring Systems (PMS). Recent technical advances have made it feasible to perform continuous real-time monitoring with significant advances in sensitivity and stability while minimizing sample tubing effects.

These improvements are realized by using a small, low-cost monitor that is dedicated to monitoring a single location. A dedicated, point-of-use monitor offers the following advantages over a conventional multi-point sampling system: continuous monitoring, no missed contamination events, sample tubing lengths reduced from 20 – 30 meters to 2 – 3 meters, and 5 – 10x better sensitivity. Improvements in sensitivity and stability are realized through a dedicated monitor approach to molecular contamination monitoring. Because the monitor is continuously sampling the same environment, sample averaging can be used in a highly effective manner to reduce the …