The disclosure addresses provision of a pellicle demounting method having excellent property with respect to reduction of contamination of a photomask. A method of demounting a pellicle, the method is provided which includes: providing a stack including a photomask, a pellicle frame, and a pellicle film that are arranged in this order; providing an electrode; and a demounting step including disposing the stack and the electrode such that the pellicle film in the stack and the electrode face each other, and applying a voltage to the electrode to generate an electrostatic attractive force, which attracts the pellicle film in a direction toward the electrode, thereby demounting the pellicle film from the photomask in the stack.

The disclosure addresses provision of a pellicle demounting method having excellent property with respect to reduction of contamination of a photomask. A method of demounting a pellicle, the method is provided which includes: providing a stack including a photomask, a pellicle frame, and a pellicle film that are arranged in this order; providing an electrode; and a demounting step including disposing the stack and the electrode such that the pellicle film in the stack and the electrode face each other, and applying a voltage to the electrode to generate an electrostatic attractive force, which attracts the pellicle film in a direction toward the electrode, thereby demounting the pellicle film from the photomask in the stack.

A pellicle includes a frame. The frame includes a check valve, wherein the check valve is configured to permit gas flow from an interior of the pellicle to an exterior of the pellicle; and a bottom surface of the frame defines only a single recess therein. The pellicle further includes a gasket configured to fit within the single recess.

A pellicle includes a frame. The frame includes a check valve, wherein the check valve is configured to permit gas flow from an interior of the pellicle to an exterior of the pellicle; and a bottom surface of the frame defines only a single recess therein. The pellicle further includes a gasket configured to fit within the single recess.

A pellicle demounting method includes providing a stack including a photomask, a pellicle frame, and a pellicle film that are arranged in this order, forming of a pressure-sensitive adhesive layer on the pellicle film in the stack, and a demounting step of demounting at least the pellicle film and the pressure-sensitive adhesive layer from the photomask in the stack having the pressure-sensitive adhesive layer formed thereon.

A pellicle demounting method includes providing a stack including a photomask, a pellicle frame, and a pellicle film that are arranged in this order, forming of a pressure-sensitive adhesive layer on the pellicle film in the stack, and a demounting step of demounting at least the pellicle film and the pressure-sensitive adhesive layer from the photomask in the stack having the pressure-sensitive adhesive layer formed thereon.

A method for preparing a pellicle assembly includes reducing the thickness of one or more initial membrane(s) to obtain a pellicle membrane. The pellicle membrane is then affixed to a mounting frame to obtain the pellicle assembly. Compressive pressure can be applied to reduce the thickness of the initial membrane(s). Alternatively, the thickness can be reduced by stretching the initial membrane(s) to obtain an extended membrane. A mounting frame is then affixed to a portion of the extended membrane. The mounting frame and the portion of the extended membrane are then separated from the remainder of the extended membrane to obtain the pellicle assembly. The resulting pellicle assemblies include a pellicle membrane that is attached to a mounting frame. The pellicle membrane can be formed from nanotubes and has a combination of high transmittance, low deflection, and small pore size.

A method for preparing a pellicle assembly includes reducing the thickness of one or more initial membrane(s) to obtain a pellicle membrane. The pellicle membrane is then affixed to a mounting frame to obtain the pellicle assembly. Compressive pressure can be applied to reduce the thickness of the initial membrane(s). Alternatively, the thickness can be reduced by stretching the initial membrane(s) to obtain an extended membrane. A mounting frame is then affixed to a portion of the extended membrane. The mounting frame and the portion of the extended membrane are then separated from the remainder of the extended membrane to obtain the pellicle assembly. The resulting pellicle assemblies include a pellicle membrane that is attached to a mounting frame. The pellicle membrane can be formed from nanotubes and has a combination of high transmittance, low deflection, and small pore size.

A filtration formed nanostructure pellicle film is disclosed. The filtration formed nanostructure pellicle film includes a plurality of carbon nanofibers that are intersected randomly to form an interconnected network structure in a planar orientation. The interconnected structure allows for a high minimum EUV transmission rate of at least 92%, with a thickness ranging from a lower limit of 3 nm to an upper limit of 100 nm, to allow for effective EUV lithography processing.

A filtration formed nanostructure pellicle film is disclosed. The filtration formed nanostructure pellicle film includes a plurality of carbon nanofibers that are intersected randomly to form an interconnected network structure in a planar orientation. The interconnected structure allows for a high minimum EUV transmission rate of at least 92%, with a thickness ranging from a lower limit of 3 nm to an upper limit of 100 nm, to allow for effective EUV lithography processing.