POLISHING AGENT FOR SYNTHETIC QUARTZ GLASS SUBSTRATES, METHOD FOR PRODUCING SAME, AND METHOD FOR POLISHING SYNTHETIC QUARTZ GLASS SUBSTRATE

摘要

The present invention is a polishing agent for synthetic quartz glass substrates, which contains polishing particles and water, and which is characterized in that: the polishing particles are composite oxide particles of cerium and yttrium; and the cerium content in the polishing particles is from 71 mol% to 79 mol% (inclusive). Consequently, the present invention is able to provide a polishing agent for synthetic quartz glass substrates, which is capable of sufficiently reducing the occurrence of defects in the surface of a synthetic quartz glass substrate due to polishing without lowering the polishing rate.