GLASS SUBSTRATE FOR MASK BLANK AND MANUFACTURING METHOD THEREOF, METHOD OF MANUFACTURING MASK BLANK, AND METHOD OF MANUFACTURING MASK

摘要

PURPOSE: A glass substrate for a mask blank, and its preparation method are provided to inhibit the deterioration of strength and to suppress the generation of scum due to the crack or distorting at the formation part of a marker. CONSTITUTION: A glass substrate for a mask blank is provided with a marker(18) which expresses the information for distinguishing or managing the glass substrate for a mask blank with a plurality of concave parts(20) on the side of the region in which there is no effect when the transfer pattern of the glass substrate for a mask blank is manufactured. The concave parts constituting the marker are a round hole whose edge is approximately circular. The distance between the adjacent concave parts at the edge is 50 micrometers or more.