US 11,953,822 B2
Reflective mask blank for EUV lithography, reflective mask for EUV lithography, and method for manufacturing same
Hirotomo Kawahara, Tokyo (JP); Daijiro Akagi, Tokyo (JP); Hiroaki Iwaoka, Tokyo (JP); Toshiyuki Uno, Tokyo (JP); Michinori Suehara, Tokyo (JP); and Keishi Tsukiyama, Tokyo (JP)
Assigned to AGC INC., Tokyo (JP)
Filed by AGC INC., Tokyo (JP)
Filed on May 18, 2023, as Appl. No. 18/198,881.
Application 18/198,881 is a continuation of application No. PCT/JP2022/005224, filed on Feb. 9, 2022.
Claims priority of application No. 2021-022583 (JP), filed on Feb. 16, 2021.
Prior Publication US 2023/0324785 A1, Oct. 12, 2023
Int. Cl. G03F 1/32 (2012.01); G03F 1/24 (2012.01); G03F 1/48 (2012.01)
CPC G03F 1/32 (2013.01) [G03F 1/24 (2013.01); G03F 1/48 (2013.01)] 18 Claims
 
1. A reflective mask blank for EUV lithography, comprising:
a substrate,
a multilayer reflective film reflecting EUV light, and
a phase shift film shifting a phase of the EUV light,
wherein the substrate, the multilayer reflective film, and the phase shift film are formed in this order,
the phase shift film comprises a layer 1 comprising ruthenium (Ru) and nitrogen (N), and
the layer 1 has an absolute value of a film stress of 1,000 MPa or less.