Cleaning of photomasks prior to pelliclizatlon Is the most demanding of all mask cleaning operations. A single particle found under a pellicle can lead to costly and time consuming repelliclization. Improved stepper resolution and automatic post pellicle inspection systems are making the requirement even more difficult to meet. Careful anal ysi s of parti culate sou rces an d clean i n g p rocesses b y Solid State Equipment Corporation have lead to the evolution of the SSEC Model 156SC which has proven to be effective as a sub micron prepellicle mask cleaner. It uses a combination of brush surfactant high pressure water static control fluid and rapid drying to achieve superior cleaning results. In an effort to meet their cleaning requirements In a cost effective manner DuPont Photomasks has installed this system in their San Jose Facility. The system design and the evaluation techniques are described. Some experimental data is presented.
Bert F. Plambeck,
Mark D. Cerio,
James A. Reynolds,
"Recent advances in prepellicle mask cleaning", Proc. SPIE 1264, Optical/Laser Microlithography III, (1 June 1990); doi: 10.1117/12.20224; https://doi.org/10.1117/12.20224