Abstract:
PROBLEM TO BE SOLVED: To provide a mask blank capable of abating the electromagnetic field (EMF) bias without suppressing the phase difference of a thin film and a mask for transfer obtained by processing this thin film.SOLUTION: In a mask blank 1 including a translucent substrate 11 and a thin film 21 configured atop the translucent substrate 11, the thin film 21 possesses, in proper order from the translucent substrate 11 side, a lower layer 13a and an upper layer 13b possessing an interface S bordering the lower layer 13a and configured adjacently to the lower layer 13a. The lower layer 13a includes not only a transition metal and silicon but also at least either of nitrogen and oxygen, whereas variations of contents of the respective elements included within the lower layer 13a along the film thickness direction thereof are 10 atom% or below. The refractive index nb of the upper layer 13b is lower than the refractive index na of the lower layer 13a, whereas the extinction coefficient kb of the same is lower than the extinction coefficient ka of the lower layer 13a.
Abstract:
PROBLEM TO BE SOLVED: To provide a mask blank and a transfer mask having a light-shielding film with a reduced EMF (electromagnetic field) bias, which greatly reduces various loads relating to the production of a transfer mask, and suppressing exposure of a resist film on a wafer by leaked light due to overlap exposure.SOLUTION: The mask blank is to be used for creating a binary mask to which ArF excimer laser exposure light is applied, and includes a light-shielding film for forming a transfer pattern on a light-transmitting substrate. The light-shielding film has a layered structure of a lower layer and an upper layer and has an optical density of 2.8 or more to exposure light. The lower layer is formed of a material comprising tantalum containing nitrogen and has a film thickness of 33 nm or more. The upper layer is formed of a material comprising tantalum containing oxygen and has a film thickness of 3 nm or more. A phase difference 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 is 60 degrees or less.