| 摘要 |
SOLUTION: To provide a photomask blank having tensile stress or compressive stress comprising a quartz substrate, and a chromium-based material film containing at least one element selected from the group consisting of nitrogen, oxygen, carbon, and hydrogen formed on the quartz substrate, where the chromium-based material film is a hard mask, the ratio (A/B) of an etching rate A per unit film thickness when etching a chromium-based material film by chlorine-based dry etching to an etching rate B per unit film thickness when etching a film composed of chromium only by chlorine-based dry etching is not less than 0.7 and not greater than 0.9, and the warpage of the chromium-based material film is not greater than 70 nm when the chromium-based material film is formed on a quartz substrate having a square of 152 mm and a thickness of 6.35 and heat-treated at not lower than 150°C for not less than 10 minutes.EFFECT: There can be provided the photomask blank having a thin film of a chromium-based material improved in etching resistance and reduced in membrane stress, whereby the highly accurate pattern production of a chromium-based film is possible.SELECTED DRAWING: None |
