REFLECTION-TYPE MASK BLANK FOR EUV LITHOGRAPHY AND METHOD FOR PRODUCING THE SAME

摘要

Provided is an EUV mask blank comprising a low-reflection layer that has excellent EUV mask blank characteristics. In particular, reflectance in the wavelength region of pattern inspection light is low and etching speed is sufficient and resist adhesion is good, and it is therefore possible to solve problems that include resist pattern loss and resist pattern defects when a fine resist pattern having a width of approximately 100 nm or less is formed in an etching process that uses a chlorine gas. A reflection-type mask blank for EUV lithography in which a reflection layer for reflecting EUV light, an absorbent layer for absorbing EUV light, and a low-reflection layer that has low reflectance with respect to mask-pattern inspection light (wavelength of 190-260 nm) are formed on a substrate in said order, wherein the low-reflection layer is a laminated structure in which a first layer having a silicon (Si) + nitrogen (N) total content of 95 at% or greater, and a second layer having a tantalum (Ta) + oxygen (O) + nitrogen (N) total content of 95 at% or greater or a second layer having a tantalum (Ta) + nitrogen (N) total content of 95 at% or greater, are laminated in said order from the absorbent layer side.