	US 12,013,631 B2
	Mask blank, transfer mask, and method for manufacturing semiconductor device
Hiroaki Shishido, Tokyo (JP)
Assigned to HOYA CORPORATION, Tokyo (JP)
Filed by HOYA CORPORATION, Tokyo (JP)
Filed on Dec. 2, 2022, as Appl. No. 18/073,794.
Application 18/073,794 is a continuation of application No. 17/397,642, filed on Aug. 9, 2021, granted, now 11,543,744.
Application 17/397,642 is a continuation of application No. 16/327,172, granted, now 11,112,690, issued on Sep. 7, 2021, previously published as PCT/JP2017/028043, filed on Aug. 2, 2017.
Claims priority of application No. 2016-165550 (JP), filed on Aug. 26, 2016.
Prior Publication US 2023/0099176 A1, Mar. 30, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G03F 1/26 (2012.01); G03F 1/50 (2012.01); G03F 1/54 (2012.01); G03F 7/20 (2006.01)

CPC G03F 1/26 (2013.01) [G03F 1/50 (2013.01); G03F 1/54 (2013.01); G03F 7/20 (2013.01)]

18 Claims

1. A mask blank comprising:

a transparent substrate; and

a light shielding film on the transparent substrate,

wherein the light shielding film includes:

a lower layer on the transparent substrate; and

an upper layer on the lower layer,

wherein the lower layer contains silicon and nitrogen,

wherein the upper layer contains silicon and oxygen,

wherein an optical density to an ArF excimer laser exposure light of the light shielding film is 2.5 or more,

wherein a surface reflectance to the exposure light of the light shielding film is 30% or less,

wherein a back-surface reflectance to the exposure light of the light shielding film is 40% or less,

wherein a transmittance to a light having a wavelength of 900 nm of the light shielding film is 50% or less,

wherein an extinction coefficient k to a light having a wavelength of 900 nm of the light shielding film is 0.04 or more, and

wherein a thickness of the light shielding film is 60 nm or less.