Resist Outgassing by EUV Irradiation

Extreme ultraviolet (EUV) lithography requires the vacuum environment for the exposure. The hydrocarbons outgassing ions species affects the reflectivity of the mask and the imaging mirror under EUV irradiation. The photo-induced outgassing was investigated for both the non-chemically amplified resists and the chemically amplified resists which can be used for EUVL. We found out the chemically amplifed positive tone resist which has low outgassing characteristics under the EUV irradiation. Furthermore, it is found that the photodecomposition occurred under EUV irradiation from the resist outgassing investigation.