PURPOSE: To realize high heat resistance and effective reduce the diffusion speed of, especially, sodium to be diffused, by using a quartz glass material containing a specified amount of chloride, and practically no OH or metallic impurity.
CONSTITUTION: Soot type silica produced by hydrolyzing silicon halogenide in oxygen-hydrogen flame is deposited. By heat-treating the obtained porous quartz glass member material in atmosphere containing chlorinated agent, quartz glass material for semiconductor heat treatment is manufactured, wherein the content of OH is less than or equal to 10ppm, metal impurity is not practically contained, and the content of chloride is adjusted in the range of 500-4000ppm. Said glass material has high heat resistance, and can effectively restrain the contamination of semiconductor caused by metal and the like, and, especially, the contamination caused by sodium whose diffusion speed is large, so that high serviceability suitable also for repetition use is obtained.
KATO TOSHIYUKI
NISHIMURA HIROYUKI
