US 12,487,517 B2
Blank mask and photomask using the same
GeonGon Lee, Seoul (KR); Suk Young Choi, Seoul (KR); Hyung-joo Lee, Seoul (KR); Suhyeon Kim, Seoul (KR); Sung Hoon Son, Seoul (KR); Seong Yoon Kim, Seoul (KR); Min Gyo Jeong, Seoul (KR); Hahyeon Cho, Seoul (KR); Taewan Kim, Seoul (KR); and Inkyun Shin, Seoul (KR)
Assigned to SK enpulse Co., Ltd., Pyeongtaek-si (KR)
Filed by SK enpulse Co., Ltd., Pyeongtaek-si (KR)
Filed on Jul. 12, 2022, as Appl. No. 17/862,508.
Claims priority of application No. 10-2021-0091497 (KR), filed on Jul. 13, 2021.
Prior Publication US 2023/0030141 A1, Feb. 2, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G03F 1/26 (2012.01)
CPC G03F 1/26 (2013.01) 18 Claims
OG exemplary drawing
 
1. A blank mask comprising a transparent substrate and a light shielding film disposed on the transparent substrate,
wherein the light shielding film comprises a transition metal and at least one selected from the group consisting of oxygen and nitrogen,
wherein the transition metal comprises Cr,
wherein when a surface of the light shielding film comprises nine sectors formed by trisecting the surface of the light shielding film vertically and horizontally, each of the nine sectors has a Rsk value, respectively, and an average value of the Rsk values of the nine sectors is equal to −0.64 or more and less than or equal to 0, where Rsk value is a height symmetry of the surface of the light shielding film measured in accordance with ISO_4287,
wherein an average value of Rku values, which are kurtosis of the surface of the light shielding film measured in accordance with ISO_4287, of the nine sectors is 3 or less,
wherein the light shielding film comprises a first light shielding layer and a second light shielding layer disposed on the first light shielding layer, and
wherein an amount of the transition metal of the second light shielding layer is greater than an amount of the transition metal of the first light shielding layer.