New type of haze formation on masks fabricated with Mo-Si blanks

In our paper we make an analysis of conditions for the haze development on photomask fabricated on Mo-Si containing substrates. We bring in focus cases of haze formation on masks with intrinsically very low contaminants level and being exposed in very well controlled atmosphere. There are clear indications that this new type of haze formation deviates from the generally accepted models not only with respect to the formation mechanisms but also with regard to the chemical composition of the haze products. In our analysis we speculate that the new haze type formation is closely related to the earlier reported CD degradation observed on Mo-Si masks. We also analyze the hypothesis that the ingredients for the haze formation are not only airborne contaminants and/or traces on the mask surface, but are also provided by the substrate material. Finally we present and discuss experimental data in the view of the advanced models.