Patent ID: 11927880
Assignee: S&S TECH CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 14:
15. A blankmask for extreme ultraviolet lithography, comprising:
a substrate;
a reflective layer formed on the substrate; and
a phase shift layer formed on the reflective laver,
wherein the phase shift layer contains niobium (Nb), chrome (Cr), and nitrogen (N),
wherein the phase shift layer has a relative reflectance of 9 to 15% with respect to the reflective layer in extreme ultraviolet exposure light having a wavelength of 13.5 nm,
wherein the phase shift layer includes a first layer and a second layer on the first layer,
wherein the first layer is configured to have a constitution ratio of Cr:Nb:N=30 to 40 at %:20 to 50 at %:10 to 50 at % and
wherein the second layer is made of a material further containing oxygen (O) of 1 to 50 at %, and has a thickness of 5 nm or less.