Pellicle fabrication methods and structures thereof
A method for fabricating a pellicle includes forming a first dielectric layer over a back surface of a substrate. After forming the first dielectric layer, and in some embodiments, a graphene layer is formed over a front surface of the substrate. In some examples, after forming the graphene layer, the first dielectric layer is patterned to form an opening in the first dielectric layer that exposes a portion of the back surface of the substrate. Thereafter, while using the patterned first dielectric layer as a mask, an etching process may be performed to the back surface of the substrate to form a pellicle having a pellicle membrane that includes the graphene layer.
1. A method, comprising:
forming a first carbon-containing layer over a front surface of a substrate;
after forming the first carbon-containing layer, patterning a hard mask layer disposed on a back surface of the substrate to expose a portion of the back surface of the substrate; and
etching the back surface of the substrate through the patterned hard mask layer to form a pellicle having a pellicle membrane that includes the first carbon-containing layer.
2. The method of claim 1 , further comprising:
prior to forming the first carbon-containing layer, forming the hard mask layer on the back surface of the substrate.
3. The method of claim 2 , wherein the hard mask layer includes a dielectric layer.
4. The method of claim 1 , wherein the first carbon-containing layer includes graphene.
5. The method of claim 1 , further comprising:
prior to forming the first carbon-containing layer, forming a dielectric layer on the front surface of the substrate;
forming a metal layer over the dielectric layer; and
forming the first carbon-containing layer over the metal layer.
6. The method of claim 5 , wherein the etching the back surface of the substrate etches a portion of the dielectric layer and a portion of the metal layer to form the pellicle having the pellicle membrane that includes the first carbon-containing layer.
7. The method of claim 1 , further comprising:
prior to forming the first carbon-containing layer over the front surface of the substrate, forming a second carbon-containing layer over the front surface of the substrate; and
forming the first carbon-containing layer over the second carbon-containing layer;
wherein the etching the back surface of the substrate forms the pellicle having the pellicle membrane that includes the first carbon-containing layer and the second carbon-containing layer.
8. The method of claim 7 , further comprising:
prior to patterning the hard mask layer, forming a first protection layer over the first carbon-containing layer; and
forming a second protection layer over the first protection layer.
9. The method of claim 8 , further comprising:
after forming the pellicle having the pellicle membrane that includes the first carbon-containing layer and the second carbon-containing layer, removing the first protection layer and the second protection layer.
10. The method of claim 1 , further comprising:
after forming the pellicle having the pellicle membrane that includes the first carbon-containing layer, forming a capping layer over the first carbon-containing layer.
11. The method of claim 7 , wherein the second carbon-containing layer includes silicon carbide (SiC).
12. The method of claim 11 , wherein a carbon content of the SiC of the second carbon-containing layer is greater than about 20%.
13. A method, comprising:
forming a carbon-containing layer over a substrate;
mounting a pellicle frame to the carbon-containing layer using an adhesive layer; and
releasing the carbon-containing layer from the substrate while the pellicle frame remains mounted to the carbon-containing layer to provide a pellicle having a pellicle membrane including the carbon-containing layer.
14. The method of claim 13 , wherein the carbon-containing layer includes graphene.
15. The method of claim 13 , further comprising:
prior to forming the carbon-containing layer over the substrate, forming a dielectric layer over the substrate, wherein the substrate includes a semiconductor substrate; and
forming the carbon-containing layer over the dielectric layer.
16. The method of claim 15 , further comprising:
forming the dielectric layer, wherein the dielectric layer includes a nitride layer; and
performing a wet etching process to release the carbon-containing layer from the nitride layer.
17. The method of claim 13 , further comprising:
forming the carbon-containing layer over the substrate, wherein the substrate includes a metal foil; and
etching the metal foil to release the carbon-containing layer from the metal foil.
18. The method of claim 13 , further comprising:
after releasing the carbon-containing layer from the substrate, forming a capping layer over the carbon-containing layer.
19. A structure, comprising:
a pellicle mounted to an EUV lithographic mask;
wherein the pellicle includes a pellicle frame and a pellicle membrane suspended by the pellicle frame a distance away from a patterned surface of the EUV lithographic mask; and
wherein the pellicle membrane includes graphene.
20. The structure of claim 19 , wherein the pellicle membrane further includes silicon carbide (SiC).