METHOD FOR PRODUCING TIO2-SIO2 GLASS BODY, METHOD FOR HEAT-TREATING TIO2-SIO2 GLASS BODY, TIO2-SIO2 GLASS BODY, AND OPTICAL BASE FOR EUVL

摘要

The present invention relates to a process for production of a TiO 2 -SiO 2 glass body, comprising a step of, when an annealing point of a TiO 2 -SiO 2 glass body after transparent vitrification is taken as T 1 (°C), holding the glass body after transparent vitrification in a temperature region of from T 1 -90 (°C) to T 1 -220 (°C) for 120 hours or more.