Method for forming a pellicle
The present disclosure relates to a method for forming a pellicle for extreme ultraviolet lithography, the method comprising: forming a coating of a first material on a peripheral region of a main surface of a carbon nanotube pellicle membrane, the membrane including a carbon nanotube film, arranging the carbon nanotube pellicle membrane on a pellicle frame with the peripheral region facing a support surface of the pellicle frame, wherein the support surface of the pellicle frame is formed by a second material, and bonding together the coating of the carbon nanotube pellicle membrane and the pellicle support surface by pressing the carbon nanotube pellicle membrane and the pellicle support surface against each other. The present disclosure relates also relates to a method for forming a reticle system for extreme ultraviolet lithography.
1. A method for forming a pellicle for extreme ultraviolet lithography, the method comprising:
forming a coating of a first material on at least a peripheral region of a main surface of a carbon nanotube pellicle membrane, the membrane including a carbon nanotube film;
arranging the carbon nanotube pellicle membrane on a pellicle frame with the peripheral region of the main surface of the carbon nanotube pellicle membrane facing a support surface of the pellicle frame, wherein the support surface of the pellicle frame is formed by a second material;
increasing a tensile stress in the carbon nanotube pellicle membrane prior to or subsequent to arranging the carbon nanotube pellicle membrane on the pellicle frame;
wherein increasing the tensile stress in the carbon nanotube pellicle membrane prior to arranging the carbon nanotube pellicle membrane on the pellicle frame further comprises stretching the carbon nanotube pellicle membrane in a lateral direction upon a stretchable support, and wherein increasing the tensile stress in the carbon nanotube pellicle membrane subsequent to arranging the carbon nanotube pellicle membrane on the pellicle frame further comprises cooling the carbon nanotube pellicle membrane to below room temperature; and
bonding together the coating of the carbon nanotube pellicle membrane and the support surface of the pellicle frame by heating the carbon nanotube pellicle membrane and the pellicle frame while applying pressure, wherein the carbon nanotube pellicle membrane and the support surface of the pellicle frame are pressed against each other.
2. The method according to claim 1 , wherein the step of bonding includes applying a vacuum having a pressure below 1 mbar to the carbon nanotube pellicle membrane and the pellicle frame.
3. The method according to claim 1 ,
wherein the support surface of the pellicle frame is formed by the first material and the coating is formed by the second material,
wherein the first material is a metal or a semiconductor, and
wherein the second material is a metal or a semiconductor.
4. The method according to claim 1 , wherein the first material and the second material are selected from the group consisting of: Zr, Mo, Ru, Pd, Nb, Ge, and Si.
5. The method according to claim 1 , wherein the first material and the second material are the same materials.
6. The method according to claim 1 , wherein the step of bonding includes pressing the carbon nanotube pellicle membrane and the support surface of the pellicle frame together by means of a mechanical pressure.
7. The method according to claim 6 , wherein the pressing the carbon nanotube pellicle membrane includes applying a pressure of 0.1 kPa to 30 MPa.
8. The method according to claim 1 , wherein the pellicle frame comprises a frame body of a third material which is different from the second material.
9. The method according to claim 8 , wherein the frame body is permeable to air.
10. The method according to claim 1 , wherein the pellicle frame is formed by Si, SiN, SiO 2 , or quartz.
11. The method according to claim 1 , wherein the coating is formed to cover an entire main surface of the carbon nanotube pellicle membrane.
12. The method according to claim 1 , wherein heating the carbon nanotube pellicle membrane and the pellicle frame includes heating the carbon nanotube pellicle membrane and the pellicle frame from 100 to 900° C.
13. A method for forming a reticle system for extreme ultraviolet lithography, the method comprising:
forming a pellicle according to claim 1 ; and
mounting the pellicle on a reticle.
14. A reticle system for extreme ultraviolet lithography, formed according to the method of claim 13 .
15. A pellicle for extreme ultraviolet lithography, the pellicle comprising:
a pellicle frame having a support surface; and
a carbon nanotube pellicle membrane including at least one carbon nanotube film,
wherein a coating of a first material is provided on at least a peripheral region of a main surface of the carbon nanotube pellicle membrane,
wherein the support surface of the pellicle frame is formed by a second material,
wherein the peripheral region of the carbon nanotube pellicle membrane is attached to the support surface of the pellicle frame by way of a heat and pressure bonding process, and
wherein the carbon nanotube pellicle membrane is under tensile stress from at least one of stretching the carbon nanotube pellicle membrane in a lateral direction upon a stretchable support, or cooling the carbon nanotube pellicle membrane below room temperature.
16. The pellicle according to claim 15 , wherein the pellicle frame and the carbon nanotube pellicle membrane are bonded together.
17. The pellicle according to claim 15 , wherein the first material and the second material are selected from the group consisting of: Zr, Mo, Ru, Pd, Nb, Ge, and Si.
18. The pellicle according to claim 15 , wherein first material and the second material are the same materials.