| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for processing a synthetic quartz glass substrate for obtaining a large-sized photomask substrate having high flatness. <P>SOLUTION: The method for processing a synthetic quartz glass substrate is characterized in that: projected portions of a large-sized synthetic quartz glass substrate having a diagonal length of not less than 500 mm and a ratio of flatness/diagonal length ranging from 36×10<SP>-6</SP>to 50×10<SP>-6</SP>are removed by sandblasting in which abrasive grains having a particle diameter of #600 to #3,000 are sprayed with air to enhance flatness in terms of the ratio of flatness/diagonal length of the glass substrate to not more than 6.0×10<SP>-6</SP>. The large-sized substrate is used for exposure, whereby the exposure accuracy, particularly the register accuracy and resolution are enhanced, so that it is possible to achieve high-definition exposure of a large sized panel. <P>COPYRIGHT: (C)2009,JPO&INPIT |
