| abstract |
In a method for cleaning photo masks having patterns with smallest line-space dimensions below 200 nm, a surfactant composition A is used, wherein A contains at least three short-chain perfluorinated groups Rf selected from the group consisting of trifluoromethyl, pentafluoroethyl, 1-heptafluoropropyl, 2-heptafluoropropyl, and pentafluorosulfanyl and wherein A exhibits, at a 1% by weight aqueous solution, a static surface tension below 25 mN/m. |