MASK FOR LASER BEAM MACHINING

PURPOSE:To form excellent wiring patterns by partially changing the number of layers of the multilayered dielectric films of a mirror mask for laser abrasion machining to be used at the time of forming semiconductor integrated circuits, thereby adjusting the transmittance of a laser beam. CONSTITUTION:The multilayered dielectric films are formed on a transparent quartz substrate 9 by alternately laminating SiO2 films and Y2O3 films by a sputtering method. In the case, the mirror mask 18 is formed by specifying the number of layers of the multilayered dielectric films 20 of the mask part to 50 layers, the number of layers of apertures 21 forming piercing holes 15 and the number of layers of the multilayered dielectric films 22 corresponding to wiring pattern forming positions to 10 layers. On the other hand, a polyamic acid is applied on a substrate 11 consisting of borosilicate glass and a resin film 19 consisting of polyimide is formed after solvent drying. After the mirror mask 8 and the substrate 11 are fixed to a frame body, the mask and the substrate are subjected to laser abrasion machining by irradiation with a laser beam 4, by which sharply pierced holes 15 are formed. The positions 23 where circumferential wiring patterns are formed are roughened to surface roughness of Q(71655 0.5 to 1.0mm, by which the adhesiveness of the resin film and the fine wiring patterns is improved.