Films for prevention of crystal growth on fused silica substrates for semiconductor lithography

A photolithography system, comprising:

• a source of radiation;
• a substrate support;
• optics adapted to couple radiation between the source and the substrate support;
• and
• a photolithographic mask disposed along an optical path between the source of radiation and the substrate support, wherein the photolithographic mask includes
• a silicon-dioxide substrate having a front surface and a back surface,
• a patterned layer disposed on the front surface, wherein the patterned layer includes a pattern that has been etched into the front surface;
• and
• a coating of a fluoride of an element of group IIA that covers the patterned layer and the front surface.

A method for photolithography, comprising:

• forming a layer of photoresist on a substrate;
• disposing a reticle proximate the layer of photoresist, wherein the reticle includes a mask substrate made of a silicon oxide material, a patterned layer on a front surface of the mask substrate, wherein the patterned layer includes a pattern that has been etched into the front surface, and a layer of a fluoride of a group IIA element that covers the patterned layer and the front surface;
• and
• exposing the photoresist to radiation that impinges on the reticle.