Substrate effects on the characteristics of haze defect formation on the photomask surface under exposure condition

We have explored substrate effects upon the characteristics of haze creation on the mask surface by performing surface analysis for each of Cr, MoSiON, and Qz substrates of the mask before and after laser exposure. We found out chemical ions such as sulfur and ammonium ions should have different mobility behavior towards haze defect creation depending on each substrate during laser exposure. This fact can partially clarify the reason why haze occurrence on the mask in real mass production mainly comes up with Qz substrate surface even though it has the lowest level of chemical residue on it. We also realized that sulfur ions are penetrating into a sub layer of Qz substrate and even deeper during laser exposure, which signifies that we may have to remove a thin surface layer from Qz substrate to further improve haze issue from the current standpoint.