Self-supporting pellicle film with HARM structure

Abstract

A method for forming a free-standing pellicle film having a high aspect ratio molecular structure (HARM structure) is disclosed, the method including the steps of a) depositing a first portion of the HARM structure onto a porous filter to form a film of the HARM structure on the porous filter, b) transferring the film of the HARM structure from the porous filter to a frame to form a free-standing film of the HARM structure attached to the frame, and c) depositing a second portion of the HARM structure onto the free-standing film of the HARM structure attached to the frame to form a free-standing pellicle film of the HARM structure attached to the frame.

Claims

[Claim 1] A method for forming a self-supporting pellicle film having a high aspect ratio molecular structure (HARM structure), a) In order to form a HARM structure film on a porous filter, the steps include depositing a first portion of the HARM structure onto the porous filter from the gas phase, b) A step of transferring the HARM structured film from the porous filter to the frame in order to form a self-supporting film with a HARM structure attached to the frame, c) A method comprising the step of depositing a second portion of a HARM structure onto the self-supporting film of the HARM structure attached to the frame, from the gas phase, in order to form a self-supporting pellicle film of the HARM structure attached to the frame. [Claim 2] When the following formula is calculated, a self-supporting pellicle film with a HARM structure exhibiting a transmittance difference value of 1% or less is formed. Transmittance difference value (%) = Maximum transmittance (%) - Minimum transmittance (%) The maximum transmittance is the maximum value of the transmittance measured at a wavelength of 550 nm for the self-supporting pellicle film with a HARM structure. The method according to claim 1, wherein the minimum transmittance is the minimum transmittance measured at a wavelength of 550 nm for the self-supporting pellicle film having a HARM structure. [Claim 3] The method according to claim 2, wherein the self-supporting pellicle film having a HARM structure exhibits a transmittance difference value of 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.35% or less, 0.33% or less, 0.30% or less, 0.25% or less, 0.20% or less, 0.15% or less, 0.10% or less, or 0.05% or less. [Claim 4] The self-supporting pellicle film with HARM structure is 1 cm ２ The method according to claim 1, wherein each includes 10 or fewer defects, 5 or fewer defects, 3 or fewer defects, 1 or fewer defects, or 0 defects. [Claim 5] The method according to claim 1, wherein the deposition of the first portion of the HARM structure is sustained until the transmittance of the film of the HARM structure is 80–99%, 85–98%, 90–96%, or 92–94% of the energy of light incident perpendicularly thereon per unit time when measured at a wavelength of 550 nm. [Claim 6] The method according to claim 1, wherein the deposition of the second portion of the HARM structure is sustained until the transmittance of the self-supporting pellicle film of the HARM structure is 50–95%, 55–93%, 60–87%, 65–86%, 70–85%, or 75–80% of the energy of light incident perpendicularly thereon per unit time when measured at a wavelength of 550 nm. [Claim 7] The method according to claim 1, wherein the deposition of the first portion of the HARM structure is sustained until the thickness of the film of the HARM structure is 3 to 50 nm, 5 to 45 nm, 7 to 40 nm, 10 to 35 nm, 15 to 30 nm, or 20 to 25 nm. [Claim 8] The method according to claim 1, wherein the deposition of the second portion of the HARM structure is sustained until the thickness of the self-supporting pellicle film of the HARM structure is 75–400 nm, 76–350 nm, 77–300 nm, 78–250 nm, 79–200 nm, 80–160 nm, 81–140 nm, 82–120 nm, 83–110 nm, 84–100 nm, or 85–90 nm. [Claim 9] The method according to claim 1, wherein the formed self-supporting pellicle film of HARM structure is set to have a predetermined transmittance value, and the deposition of the first portion of the HARM structure is continued until the HARM structure film exhibits a transmittance of 75-15%, 65-35%, or 55-35%, which are the predetermined transmittance values. [Claim 10] The method according to claim 1, wherein the frame is made of a polymer, quartz, titanium, graphite, silicon, silicon carbide, silicon nitrate, polysilicon, a transition metal, or an alloy of a transition metal. [Claim 11] The method according to claim 1, further comprising the step of depositing at least one further portion of a HARM structure or other nanomaterial onto the self-supporting pellicle film. [Claim 12] The method according to claim 1, wherein the HARM structure is a carbon nanostructure. [Claim 13] The method according to claim 1, further comprising the step of retransferring the formed HARM structured self-supporting pellicle film, which has been attached to the frame, from the frame to a second frame, wherein the size of the second frame is smaller than the size of the frame, and the second frame is pressed through the HARM structured self-supporting pellicle film attached to the frame in order to stretch the HARM structured self-supporting pellicle film. [Claim 14] The method according to claim 1, wherein the self-supporting pellicle film is a pellicle film such as an extreme ultraviolet film for extreme ultraviolet lithography, an extreme ultraviolet debris filter, or a pellicle film for an X-ray window.

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