| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a quartz glass having ability to inhibit diffusion of metal impurities and showing a high viscosity at high temperature, since natural silica fused quartz glass generally used so far for a semiconductor heat treatment tool does not have ability to inhibit diffusion of metal impurities, particularly copper. <P>SOLUTION: High purity synthetic silica powder is crystallized in a natural inert atmosphere and melted in an electric furnace or plasma-melted to achieve an oxygen deficiency defect ODCII content of ≤10×10<SP POS="POST">15</SP>/cm<SP POS="POST">3</SP>, an Si lone electron pair content of ≤2×10<SP POS="POST">15</SP>/cm<SP POS="POST">3</SP>and a contained Na concentration of ≤0.03 wt. ppm, whereby the objective quartz glass having ability to inhibit diffusion of metal impurities and showing a high viscosity coefficient in semiconductor heat treatment is obtained. <P>COPYRIGHT: (C)2012,JPO&INPIT |
