HIGHLY UNIFORM SYNTHETIC QUARTZ GLASS FOR OPTICAL USE, AND ITS PRODUCING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a highly uniform quartz glass suitable for an optical use, especially suitable for a lithography device, a method of producing the quartz glass, and especially, a heat treatment method by which lowering of the transmissivity caused by process contamination is suppressed. SOLUTION: A columnar synthetic quartz glass to be treated is housed in a cylindrical synthetic quartz glass vessel having a cap and the ratio of the diameter to the height of >=1.8 and is heat-treated in a heating furnace.