| 摘要 |
PURPOSE: A mask blank is provided to be able to form a marker in which a dust generation possibility on a glass substrate is very low, and to be able to effectively reuse a glass substrate or a mask blank. CONSTITUTION: A mask blank (10) comprises a glass substrate (12), and a thin film (14) for a mask pattern which becomes a mask pattern formed on the glass substrate. The glass substrate is formed by irradiating laser light on the mirror shape surface, and includes a concave part (20) which is used as a marker. The concave part is a region except 1.2 mm from both ends of the main surface, in the cross-section orthogonal to the main surface, in which the thin film for a mask pattern is formed in the surface of the glass substrate, and formed in a region within 10 mm from the four corners of the glass substrate. The marker is to indicate the characteristic identification information, identification symbol or management symbol on the mask blank. The marker corresponds to the thin film information about the thin film for a mask pattern. The thin film information is the information including at least one among the physical characteristic, the chemical characteristic, the electrical characteristic and the optical characteristic of the thin film for a mask pattern, the surface morphology of the thin film surface, defects and the deposition condition. |
