Pellicle for photomask and method of fabricating the same
A pellicle for a photomask comprises a pellicle membrane. The pellicle membrane includes a base layer having a first surface and a second surface facing the first surface, and a first recovery layer covering the first surface of the base layer. A content of SP2 covalent bonds between carbon atoms contained in the first recovery layer is less than or equal to a content of SP2 covalent bonds between carbon atoms contained in the base layer.
1. A pellicle for a photomask, the pellicle comprising a pellicle membrane, wherein the pellicle membrane comprises:
a base layer that has a first surface and a second surface facing each other; and
a first recovery layer that covers the first surface of the base layer,
wherein a content of SP2 covalent bonds between carbon atoms contained in the first recovery layer is equal to or less than a content of SP2 covalent bonds between carbon atoms contained in the base layer.
2. The pellicle of claim 1 , wherein a content of nitrogen, hydrogen, or oxygen contained in the first recovery layer is greater than a content of nitrogen, hydrogen, or oxygen contained in the base layer.
3. The pellicle of claim 1 , wherein the pellicle membrane further includes a support layer disposed at least one of between the base layer and the first recovery layer and on the second surface of the base layer,
wherein the base layer has a crystal structure different from the support layer.
4. The pellicle of claim 3 , wherein
the base layer includes at least one of graphene and graphite, and
the support layer includes at least one of diamond-like carbon (DLC) and carbon nanotube.
5. The pellicle of claim 3 , wherein the support layer includes at least one of iron, cobalt, and nickel.
6. The pellicle of claim 3 , wherein a tensile strength in a thickness direction of the base layer is less than a tensile strength in a thickness direction of the support layer.
7. The pellicle of claim 1 , wherein the pellicle membrane further includes a capping layer disposed at least one of on the first recovery layer and on the second surface of the base layer,
wherein the capping layer includes at least one of boron, boron carbide, and boron nitride.
8. The pellicle of claim 1 , wherein a D/G intensity ratio in a Raman spectrum of the pellicle membrane falls within a range of about 0 to 1.
9. The pellicle of claim 1 , wherein the pellicle membrane has an absorption coefficient of about 0.01 or less with respect to light whose wavelength is about 13.5 nm.
10. The pellicle of claim 1 , wherein the pellicle membrane has a tensile strength of about 200 MPa to about 3 GPa.
11. The pellicle of claim 1 , wherein
the base layer includes a first pinhole on the first surface, and
the first recovery layer fills the first pinhole.
12. The pellicle of claim 11 , wherein the base layer further includes a second pinhole on the second surface,
wherein the pellicle membrane further includes a second recovery layer that covers the second surface of the base layer and fills the second pinhole,
wherein a content of SP2 covalent bonds between carbon atoms contained in the second recovery layer is equal to or less than the content of SP2 covalent bonds between carbon atoms contained in the base layer.
13. A pellicle for a photomask, the pellicle comprising a pellicle membrane, wherein the pellicle membrane includes:
a base layer that has a first surface and a second surface facing each other;
a first recovery layer that covers the first surface of the base layer; and
a support layer that covers the second surface of the base layer,
wherein all of the base layer, the first recovery layer, and the support layer contain carbon atoms,
wherein a content of SP2 covalent bonds between the carbon atoms contained in the first recovery layer is equal to or less than a content of SP2 covalent bonds between the carbon atoms contained in the base layer.
14. The pellicle of claim 13 , wherein a content of nitrogen, hydrogen, or oxygen contained in the first recovery layer is greater than a content of nitrogen, hydrogen, or oxygen contained in the base layer.
15. The pellicle of claim 13 , wherein a tensile strength in a thickness direction of the base layer is less than a tensile strength in a thickness direction of the support layer.
16. The pellicle of claim 13 , wherein the content of SP2 covalent bonds between the carbon atoms contained in the first recovery layer is equal to or less than a content of SP2 covalent bonds between the carbon atoms contained in the support layer.
17. The pellicle of claim 13 , wherein the pellicle membrane further includes a capping layer disposed at least one of on the first recovery layer and on the support layer,
wherein the capping layer includes at least one of boron, boron carbide, and boron nitride.
18. The pellicle of claim 13 , wherein a content of nitrogen, hydrogen, or oxygen contained in the first recovery layer is greater than a content of nitrogen, hydrogen, or oxygen contained in the support layer.
19. The pellicle of claim 13 , wherein
the base layer includes at least one of graphene and graphite, and
the support layer includes at least one of diamond-like carbon (DLC) and carbon nanotube.
20. The pellicle of claim 13 , wherein
the base layer includes at least one first pinhole on the first surface, and
the first recovery layer fills the first pinhole.