Innovative processes investigation for photomask pod conditioning and drying

Contamination and especially Airbone Molecular Contamination (AMC) is a critical issue for mask material flow with a severe and fairly unpredictable risk of induced contamination and damages especially for 193 nm lithography. It is therefore essential to measure, to understand and then try to reduce AMC in mask environment. Results and assessment of mask pod environment in term of molecular contamination was presented in a first step. Then in second step further studies was carried out within European CRYSTAL project in order to reduce mask pod influence and contamination due to material out gassing. Results are shown here. These studies were carried out in the frame of the European R&D project, the so called "CRYSTAL" project, focusing on photomask defect reduction.