| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a mask blank which has a light-shielding film with a reduced EMF (electromagnetic field) bias, achieves significant decrease in various loads relating to the manufacture of a transfer mask, as well as satisfies such a condition that the light-shielding film ensures enough optical density to suppress exposure of a resist film on a wafer by leaked light in overlap exposure.SOLUTION: The mask blank is used for forming a binary mask to which ArF excimer laser exposure light is applied, and has a light-shielding film on a light-transmitting substrate. The light-shielding film has a layered structure of a lower layer and an upper layer, has an optical density of 2.8 or more to exposure light and has a film thickness of 45 nm or less. The lower layer comprises a material having a total content of transition metals and silicon of 90 atomic% or more, and has a film thickness of 30 nm or more. The upper layer has a film thickness of 3 nm or more and 6 nm or less. The mask blank gives a retardation of 30 degrees or less between exposure light transmitted through the light-shielding film and exposure light transmitted through air in a distance equal to the film thickness of the light-shielding film.</p> |
