Low-expansion glass substrate for a reflective mask and reflective mask

摘要

A low-expansion glass substrate for a reflective mask, wherein the glass substrate is suited for a base material of a reflective mask employed in a lithographic process in semiconductor fabrication, comprises a lateral surface, a chamfered portion and a notched portion formed along an outer periphery thereof, at least one of the lateral surface, the chamfered portion and the notched portion being provided with a mirror-finished surface.