US 12,461,439 B2
Blank mask and photomask using the same
GeonGon Lee, Seoul (KR); Hahyeon Cho, Seoul (KR); Inkyun Shin, Seoul (KR); Seong Yoon Kim, Seoul (KR); Suk Young Choi, Seoul (KR); Hyung-joo Lee, Seoul (KR); Suhyeon Kim, Seoul (KR); Sung Hoon Son, Seoul (KR); Min Gyo Jeong, Seoul (KR); and Taewan Kim, Seoul (KR)
Assigned to SK enpulse Co., Ltd., Pyeongtaek-si (KR)
Filed by SK enpulse Co., Ltd., Pyeongtaek-si (KR)
Filed on Apr. 26, 2022, as Appl. No. 17/729,419.
Claims priority of application No. 10-2021-0055698 (KR), filed on Apr. 29, 2021.
Prior Publication US 2022/0357647 A1, Nov. 10, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G03F 1/32 (2012.01)
CPC G03F 1/32 (2013.01) 18 Claims
OG exemplary drawing
 
1. A blank mask comprising:
a transparent substrate comprising an upper side and a back side where an exposure light is incident; and
a light shielding film disposed on the upper side of the transparent substrate,
wherein the light shielding film is for patterning,
wherein the light shielding film blocks at least some portion of the exposure light,
wherein the light shielding film comprises a transition metal and at least one selected from the group consisting of oxygen and nitrogen,
wherein the light shielding film comprises a first light shielding layer and a second light shielding layer disposed on the first light shielding layer,
wherein the second light shielding layer comprises a transition metal in an amount of 55 to 75 at %,
wherein the first light shielding layer comprises a transition metal in an amount of 35 to 55 at %,
wherein a Mtr value of Equation 1 below of a surface of the light shielding film is 0.5 to 4,
wherein the light shielding film has an optical density of 1.8 or more for a light with a wavelength of 193 nm:
Mtr=|Rsk|*Rku  [Equation 1]
where, in the Equation 1, |Rsk| is an absolute value of an Rsk value, which is a height skewness of the surface of the light shielding film, and Rku is kurtosis of the surface of the light shielding film,
wherein the Rsk value is −1 or more,
wherein the light shielding film comprises a first light shielding layer and a second light shielding layer disposed on the first light shielding layer,
wherein a film thickness of the first light shielding layer is 250 to 650 Å and a film thickness of the second light shielding layer is 30 to 200 Å, and
wherein a sum of an amount of the nitrogen and the oxygen in the second light shielding layer is 10 to 35 at %.