Glass substrate for a mask blank, method of producing a glass substrate for a mask blank, mask blank, method of producing the mask blank, transfer mask, and method of producing a transfer mask

摘要

In a method of producing a glass substrate for an electronic device whereby to fabricate a glass substrate by carrying out a rough polishing step for polishing a surface of the glass substrate by using relatively large abrasive particles, then a precision polishing step for polishing it by using relatively small abrasive particles, a method of producing a glass substrate for an electronic device, and a photo mask blank and a method of producing a photo mask, wherein, before carrying out the precision polishing step, the surface of the glass substrate is etched (preferably etched with an alkaline aqueous solution) so as to elicit a crack extending in the depth direction from the surface of the glass substrate, the crack remaining after the precision polishing step, in a defect inspection step carried out after the precision polishing step.