Lithographic apparatus

1. A reflector comprising a reflecting surface or structure provided with a layer, the layer comprising a substance selected from Silicene, or a Silicene derivative, or combinations thereof.

2. The reflector according to claim 1 , wherein the layer is a single layer.

3. The reflector according to claim 1 , wherein the layer comprises multiple layers, and wherein at least one layer from the multiple layers comprises a substance selected from Silicene, or a Silicene derivative, or combinations thereof.

4. The reflector according to claim 1 , wherein the layer is a cap layer.

5. The reflector according to claim 1 , wherein the reflector is a multilayer mirror comprising alternating layers of a first material and a second material, and wherein a layer comprising a substance selected from Silicene, or a Silicene derivative, or combinations thereof, is provided between at least two of the alternating layers.

6. A reflector comprising a reflecting surface or structure comprising a substance selected from Silicene, or a Silicene derivative or combinations thereof.

7. The reflector according to claim 1 , wherein the reflecting structure is a multilayer stack.

8. The reflector according to claim 1 , wherein the reflecting surface is metal.

9. A method of applying a cap layer to a reflector comprising

forming a layer comprising a substance selected from Silicene, or a Silicene derivative, or combinations thereof, on a material,

pressing the layer onto a surface of the reflector,

then etching away the material such that a cap layer comprising a substance selected from Silicene, or a Silicene derivative, or combinations thereof, is formed on the reflector.

10. A lithographic mask comprising a patterned reflective surface or structure provided with a layer or a pellicle comprising a substance selected from Silicene, or a Silicene derivative, or fullerene, or a fullerene derivative, or combinations thereof.

11. A membrane for debris mitigation comprising a substance selected from Silicene, or a Silicene derivative, or fullerene, or a fullerene derivative, or combinations thereof, held by a supporting structure.

12. An apparatus comprising one or more of:

a reflector comprising a reflecting surface or structure provided with a layer, the layer comprising a substance selected from Silicene, or a Silicene derivative, or combinations thereof, or

a pellicle for a lithographic mask comprising a substance selected from Silicene, or a Silicene derivative, or fullerene, or a fullerene derivative, or combinations thereof, or

a support to hold a lithographic mask comprising a patterned reflective surface or structure provided with a layer or a pellicle comprising a substance selected from Silicene, or a Silicene derivative, or fullerene, or a fullerene derivative, or combinations thereof, or

a membrane for debris mitigation comprising a substance selected from Silicene, or a Silicene derivative, or fullerene, or a fullerene derivative, or combinations thereof, held by a supporting structure.

13. The apparatus according to claim 12 , wherein the apparatus further comprises one or more of the following elements:

an illumination system configured to condition a radiation beam;

a support constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam;

a substrate table constructed to hold a substrate; and

a projection system configured to project the patterned radiation beam onto a target portion of the substrate.