Blank mask and photomask using the same
The present disclosure relates to a blank mask including: 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, and wherein a Mtr value of Equation 1 below of a surface of the light shielding film is 6 or less: 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.
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 %.
2 . The blank mask of claim 1 , wherein the Rsk value is 1 or less.
3 . The blank mask of claim 1 , wherein the Rku value is 6 or less.
4 . The blank mask of claim 1 , wherein a Dw value of Equation 2 below of the light shielding film is 0.01% or less:
D
w
=
D
s
-
D
o
D
o
×
1
0
0
(
%
)
[
Equation
2
]
where, in the Equation 2, Ds is a weight of the blank mask measured after forming a photoresist film of 1300 Å thickness on the light shielding film and removing the photoresist film, and Do is a weight of the blank mask measured before forming the photoresist film on the light shielding film.
5 . The blank mask of claim 1 , wherein the transition metal comprises at least any one selected from the group consisting of Cr, Ta, Ti and Hf.
6 . The blank mask of claim 1 , wherein the light shielding film is treated by cooling with cooling water directly sprayed onto the surface of the light shielding film.
7 . A photomask comprising:
a transparent substrate comprising an upper side and a back side where an exposure light is incident; and
a light shielding pattern film disposed on the upper side of the transparent substrate,
wherein the light shielding film blocks at least some portion of the exposure light,
wherein the light shielding pattern 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 pattern 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 pattern film, and Rku is kurtosis of the surface of the light shielding pattern film,
wherein the Rsk value is −1 or more,
wherein the light shielding pattern film comprises a first light shielding layer and a second light shielding layer disposed on the first light shielding layer, and
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 %.
8 . The photomask of claim 7 , wherein the Rsk value is 1 or less.
9 . The photomask of claim 7 , wherein the Rku value is 6 or less.
10 . The photomask of claim 7 , wherein the transition metal comprises at least one selected from the group consisting of Cr, Ta, Ti and Hf.
11 . A method of manufacturing a blank mask comprising:
disposing a transparent substrate and a sputtering target in a sputtering chamber;
injecting an atmosphere gas into the sputtering chamber, supplying an electric power to the sputtering target, sputtering a light shielding, and thereby forming a light shielding film coated substrate, in which the light shielding film is formed on the transparent substrate;
performing thermal treatment for 5 to 30 minutes at 150 to 330° C. to the light shielding film coated substrate and thereby forming a heated substrate; and
spraying a cooling water directly onto a surface of the transparent substrate and a surface of the light shielding film of the heated substrate and thereby manufacturing the blank mask.
12 . The method of claim 11 , further comprising stabilizing the heated substrate for 1 to 5 minutes at 30 to 50° C.
13 . The method of claim 11 , wherein a temperature of the cooling water is 10 to 30° C.
14 . The method of claim 11 , wherein the cooling water is sprayed in a flow rate of 0.5 to 1.5 L/min.
15 . The method of claim 11 , wherein the cooling water is sprayed at an angle of 30 to 75° with the surface of the light shielding film.
16 . The method of claim 11 , wherein a nozzle to spray the cooling water is disposed over the surface of the light shielding film and spaced apart by 5 to 20 mm from the surface of the light shielding film.
17 . The method of claim 11 , wherein two or more nozzles to spray the cooling water are disposed over one surface of the blank mask and an angle between the two or more nozzles when observed from the one surface is 60 degrees or more.
18 . The method of claim 11 , wherein the thermal treatment comprises a primary thermal treatment and a secondary thermal treatment.