Pellicles play a pivotal role as ultrathin, freestanding protective membranes within extreme Ultraviolet (EUV) lithography machines of ASML, safeguarding reticles against particle deposition. These ASML scanners subject these pellicles to challenging conditions, including a complex mix of EUV photons, hydrogen radicals, and plasma, at elevated temperatures which can induce chemical alterations and various forms of degradation, including dewetting and blistering of layers. Yet, the distinct impact of these conditions on pellicle lifetime remains underexplored.
In this research, we meticulously investigated the individual effects of hydrogen radicals and vacuum EUV light on materials resembling EUV pellicles, while systematically varying the temperature. Our study concentrated on 50 nm thick semi-amorphous SiN thin films.
Our findings reveal that exposure of pellicles to hydrogen radicals only did not induce any discernible chemical, structural, or morphological changes in the SiN thin film. In stark contrast, vacuum EUV photons triggered both chemical and morphological alterations, even at relatively low temperatures of 50°C.
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