| 摘要 |
PROBLEM TO BE SOLVED: To provide a glass board for electronic device, a photo-mask blank using such a glass board and a photo-mask, whereby high precision patterning and projective photo-exposure are made practicable. SOLUTION: A photo-mask blank as one sort of glass board for an electronic device is composed of a glass board 1 and a chromium film 2 having a light shutoff function. The board 1 cinsists of a quarts glass material whose major surface and side faces are fine polished. The board 1 is free of flaw having dependency in the advancing direction of the inspecting beam of light owing to an optical flaw inspection, and there are no striae inside the board 1, and flaws existing at the surface of the board 1 have confirmedly a width (length along the shorter axis) smaller than one μm. From this blank, a photo-mask is fabricated, where the chromium film pattern 2' has no flaw resulting from etching, and the desired pattern formation is obtained. By this photo-mask, patterns are transcribed on the object, where good workmanship of pattern transcription is accomplished. |
