Systems and methods for lithography masks

Abstract

Structure of mask blanks and masks, and methods of making masks are disclosed. The new mask blank and mask comprise a tripe etching stop layer to prevent damages to the quartz substrate when the process goes through etching steps three times. The triple etching stop layer may comprise a first sub-layer of tantalum containing nitrogen (TaN), a second sub-layer of tantalum containing oxygen (TaO), and a third sub-layer of TaN. Alternatively, the triple etching stop layer may comprise a first sub-layer of SiON material, a second sub-layer of TaO material, and a third sub-layer of SiON material. Another alternative may be one layer of low etching rate MoxSiyONz material which can prevent damages to the quartz substrate when the process goes through etching steps three times. The island mask is defined on the mask blank by using various optical proximity correction rules.

Dependencies are inferred from the claim text.