METHOD OF CLEANING POLISHED QUARTZ GLASS SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a scrub cleaning method for a polished quartz glass substrate which makes no flaws and has high cleaning effect as a cleaning method for a quartz substrate to be used for a photomask etc.SOLUTION: Foreign matter which may damage the substrate by being mixed with a scrub material during scrub cleaning is removed by the two fluid jet cleaning, and then scrub cleaning is carried out using the scrub material having a 30% compressive elastic modulus of elasticity of 20 to 100 kPa and a compressive elastic modulus of elasticity of 50 to 200 kPa at 20 kPa to suppress damaging due to the scrub cleaning and also to remove deposits from not only a principal surface of the substrate, but also up to an end surface.