BLANK MASK AND PHOTOMASK USING THE SAME
A blank mask includes a transparent substrate and a light shielding film disposed on the transparent substrate. A surface of the light shielding film has a controlled power spectrum density value at a spatial frequency of 1 μm −1 to 10 μm −1 . The surface of the light shielding film has a controlled minimum power spectrum density value at the spatial frequency of 1 μm −1 to 10 μm −1 . An Rq value of the surface of the light shielding film is 0.25 nm to 0.55 nm.
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 first light shielding layer and a second light shielding layer disposed on the first light shielding layer,
the second light shielding layer comprises a transition metal and at least one of oxygen and nitrogen,
a surface of the light shielding film has a power spectrum density value of 18 nm 4 or more and 50 nm 4 or less at a spatial frequency of 1 μm −1 or more and 10 μm −1 or less,
the surface of the light shielding film has a minimum power spectrum density value of 18 nm 4 or more and less than 40 nm 4 at the spatial frequency of 1 μm −1 or more and 10 μm −1 or less, and
an Rq value of the surface of the light shielding film is 0.25 nm or more and 0.55 nm or less, and the Rq value is a value evaluated by ISO_4287.
2 . The blank mask of claim 1 , wherein the surface of the light shielding film has a maximum power spectrum density value of 28 nm 4 or more and 50 nm 4 or less at the spatial frequency of 1 μm −1 or more and 10 μm −1 or less.
3 . The blank mask of claim 1 , wherein the surface of the light shielding film has a value of 70 nm 4 or less obtained by subtracting a minimum value from a maximum value of the power spectrum density at the spatial frequency of 1 μm −1 or more and 10 μm −1 or less.
4 . The blank mask of claim 1 , wherein an etching rate of the second light shielding layer measured by etching with argon gas is 0.3 Å/s or more and 0.5 Å/s or less.
5 . The blank mask of claim 1 , wherein an etching rate of the first light shielding layer measured by etching with argon gas is 0.56 Å/s or more and 1 Å/s or less.
6 . The blank mask of claim 1 , wherein an etching rate of the light shielding film measured by etching with a chlorine-based gas is 1.5 Å/s or more and 3 Å/s or less.
7 . The blank mask of claim 1 , wherein the second light shielding layer comprises the transition metal of 30 at % or more and 80 at % or less, and the nitrogen of 5 at % or more and 30 at % or less.
8 . The blank mask of claim 1 , wherein the transition metal comprises at least one of Cr, Ta, Ti and Hf, and further comprises at least one of the transition metal of groups 7 to 12.
9 . The blank mask of claim 8 , wherein the transition metal of groups 7 to 12 includes Mn, Fe, Co, Ni, Cu and Zn.
10 . A photomask comprising:
a transparent substrate; and
a light shielding pattern film disposed on the transparent substrate,
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,
the second light shielding layer comprises a transition metal and at least one of oxygen and nitrogen,
an upper surface of the light shielding pattern film has a power spectrum density value of 18 nm 4 or more and 50 nm 4 or less at a spatial frequency of 1 μm −1 or more and 10 μm −1 or less,
the upper surface of the light shielding pattern film has a minimum power spectrum density value of 18 nm 4 or more and less than 40 nm 4 at the spatial frequency of 1 μm −1 or more and 10 μm −1 or less, and
an Rq value of the upper surface of the light shielding pattern film is 0.25 nm or more and 0.55 nm or less, and the Rq value is a value evaluated by ISO_4287.
11 . The photomask of claim 10 , wherein the upper surface of the light shielding pattern film has a maximum power spectrum density value of 28 nm 4 or more and 50 nm 4 or less at the spatial frequency of 1 μm −1 or more and 10 μm −1 or less.
12 . The photomask of claim 10 , wherein the upper surface of the light shielding pattern film has a value of 70 nm 4 or less obtained by subtracting a minimum value from a maximum value of the power spectrum density at the spatial frequency of 1 μm −1 or more and 10 μm −1 or less.
13 . The photomask of claim 10 , wherein an etching rate of the second light shielding layer measured by etching with argon gas is 0.3 Å/s or more and 0.5 Å/s or less.
14 . The photomask of claim 10 , wherein an etching rate of the first light shielding layer measured by etching with argon gas is 0.56 Å/s or more and 1 Å/s or less.
15 . The photomask of claim 10 , wherein an etching rate of the light shielding pattern film measured by etching with a chlorine-based gas is 1.5 Å/s or more and 3 Å/s or less.
16 . The photomask of claim 10 , wherein the second light shielding layer comprises the transition metal of 30 at % or more and 80 at % or less, and the nitrogen of 5 at % or more and 30 at % or less.
17 . The photomask of claim 10 , wherein the transition metal comprises at least one of Cr, Ta, Ti and Hf, and further comprises at least one of the transition metal of groups 7 to 12.
18 . The photomask of claim 17 , wherein the transition metal of groups 7 to 12 includes Mn, Fe, Co, Ni, Cu and Zn.
19 . A method of manufacturing a semiconductor device, the method comprising:
disposing a light source, a photomask, and a semiconductor wafer coated with a resist film;
selectively transmitting light incident from the light source through the photomask onto the semiconductor wafer; and
developing a pattern on the semiconductor wafer, wherein:
the photomask comprises a transparent substrate and a light shielding pattern film disposed on the transparent substrate,
the light shielding pattern film comprises a first light shielding layer and a second light shielding layer disposed on the first light shielding layer,
the light shielding pattern film comprises at least one of a transition metal, oxygen, and nitrogen,
an upper surface of the light shielding pattern film has a power spectrum density value of 18 nm 4 or more and 50 nm 4 or less at a spatial frequency of 1 μm −1 or more and 10 μm −1 or less,
the upper surface of the light shielding pattern film has a minimum power spectrum density value of 18 nm 4 or more and less than 40 nm 4 at the spatial frequency of 1 μm −1 or more and 10 μm −1 or less, and
an Rq value of the upper surface of the light shielding pattern film is 0.25 nm or more and 0.55 nm or less, and the Rq value is a value evaluated by ISO_4287.