	US 12,124,164 B2
	Reflective mask blank and reflective mask
Daijiro Akagi, Tokyo (JP); Takuma Kato, Tokyo (JP); Keishi Tsukiyama, Tokyo (JP); Toshiyuki Uno, Fukushima (JP); Hiroshi Hanekawa, Tokyo (JP); Ryusuke Oishi, Fukushima (JP); Sadatatsu Ikeda, Fukushima (JP); Yukihiro Iwata, Fukushima (JP); and Chikako Hanzawa, Fukushima (JP)
Assigned to AGC Inc., Tokyo (JP)
Filed by AGC Inc., Tokyo (JP)
Filed on Mar. 29, 2024, as Appl. No. 18/621,502.
Application 18/621,502 is a continuation of application No. PCT/JP2023/025748, filed on Jul. 12, 2023.
Claims priority of application No. 2022-117803 (JP), filed on Jul. 25, 2022.
Prior Publication US 2024/0241433 A1, Jul. 18, 2024
Int. Cl. G03F 1/24 (2012.01); G03F 1/48 (2012.01)

CPC G03F 1/24 (2013.01) [G03F 1/48 (2013.01)]

7 Claims

1. A reflective mask blank, comprising in an order of reciting:

a substrate;

a multilayered reflection film configured to reflect EUV rays;

a protection film configured to protect the multilayered reflection film; and

an absorption film configured to absorb the EUV rays,

wherein the protection film contains Rh as a main component,

the multilayered reflection film includes an uppermost layer that is closest to the protection film in the multilayered reflection film and contains Si and N,

in the uppermost layer, an element ratio (N/Si) of N to Si is greater than 0.00 and less than 1.50, and an element ratio (O/Si) of O to Si is 0.00 or greater and less than 0.44, and

the reflective mask blank comprises a reflectance adjusting film containing Ru as a main component between the multilayered reflection film and the protection film.