A method comprising the steps of receiving a mask assembly comprising a mask and a removable EUV transparent pellicle held by a pellicle frame, removing the pellicle frame and EUV transparent pellicle from the mask, using an inspection tool to inspect the mask pattern on the mask, and subsequently attaching to the mask an EUV transparent pellicle held by a pellicle frame. The method may also comprise the following steps: after removing the pellicle frame and EUV transparent pellicle from the mask, attaching to the mask an alternative pellicle frame holding an alternative pellicle formed from a material which is substantially transparent to an inspection beam of the inspection tool; and after using an inspection tool to inspect the mask pattern on the mask, removing the alternative pellicle held by the alternative pellicle frame from the mask in order to attach to the mask the EUV transparent pellicle held by the pellicle frame.

A method comprising the steps of receiving a mask assembly comprising a mask and a removable EUV transparent pellicle held by a pellicle frame, removing the pellicle frame and EUV transparent pellicle from the mask, using an inspection tool to inspect the mask pattern on the mask, and subsequently attaching to the mask an EUV transparent pellicle held by a pellicle frame. The method may also comprise the following steps: after removing the pellicle frame and EUV transparent pellicle from the mask, attaching to the mask an alternative pellicle frame holding an alternative pellicle formed from a material which is substantially transparent to an inspection beam of the inspection tool; and after using an inspection tool to inspect the mask pattern on the mask, removing the alternative pellicle held by the alternative pellicle frame from the mask in order to attach to the mask the EUV transparent pellicle held by the pellicle frame.

Disclosed are a mask assembly, and a method for assembling the same. The mask assembly includes: a frame including a hollow area; a mask arranged across the hollow area, wherein two opposite ends of the mask are fixed on the frame; and first support sheets configured to support the mask, wherein the first support sheets include first sub-support sheets and second sub-support sheets stacked over each other, the first sub-support sheets and the second sub-support sheets are arranged across the hollow area of the frame, and two opposite ends of each of the first sub-support sheets, and two opposite ends of each of the second sub-support sheets are fixed on the frame; wherein orthographic projections of the first sub-support sheets onto the second sub-support sheets lie into the second sub-support sheets; and the thickness of the second sub-support sheets is smaller than the thickness of the first sub-support sheets.

Disclosed are a mask assembly, and a method for assembling the same. The mask assembly includes: a frame including a hollow area; a mask arranged across the hollow area, wherein two opposite ends of the mask are fixed on the frame; and first support sheets configured to support the mask, wherein the first support sheets include first sub-support sheets and second sub-support sheets stacked over each other, the first sub-support sheets and the second sub-support sheets are arranged across the hollow area of the frame, and two opposite ends of each of the first sub-support sheets, and two opposite ends of each of the second sub-support sheets are fixed on the frame; wherein orthographic projections of the first sub-support sheets onto the second sub-support sheets lie into the second sub-support sheets; and the thickness of the second sub-support sheets is smaller than the thickness of the first sub-support sheets.

A pellicle removal tool including a stage that holds a photomask and an associated pellicle, two or more arms positioned around the stage and configured to engage pellicle side wells of the pellicle, and two or more actuators each configured to adjust at least a vertical position of a corresponding one of the two or more arms so as to apply a lifting force to the pellicle for removal of the pellicle from the photomask.

A pellicle removal tool including a stage that holds a photomask and an associated pellicle, two or more arms positioned around the stage and configured to engage pellicle side wells of the pellicle, and two or more actuators each configured to adjust at least a vertical position of a corresponding one of the two or more arms so as to apply a lifting force to the pellicle for removal of the pellicle from the photomask.

A pellicle membrane includes a film consisting of an organic material and an inorganic material, wherein a region containing an organic material and a region consisting of an inorganic material are present in the same plane of the film, and wherein at least a central portion of the film is a region consisting of an inorganic material, and at least a peripheral edge portion of the film is a region containing an organic material.

A pellicle membrane includes a film consisting of an organic material and an inorganic material, wherein a region containing an organic material and a region consisting of an inorganic material are present in the same plane of the film, and wherein at least a central portion of the film is a region consisting of an inorganic material, and at least a peripheral edge portion of the film is a region containing an organic material.

A photo mask assembly including a photo mask, a first adhesive layer adhered with the photo mask, a pellicle frame and a pellicle is provided. The pellicle frame includes a plurality of recesses for accommodating the first adhesive layer. The pellicle frame is adhered with the photo mask through the first adhesive layer accommodated in the plurality of recesses. The pellicle is disposed on the pellicle frame. The pellicle frame is between the pellicle and the first adhesive layer. An optical apparatus including the above-mentioned photo mask assembly is also provided.

A photo mask assembly including a photo mask, a first adhesive layer adhered with the photo mask, a pellicle frame and a pellicle is provided. The pellicle frame includes a plurality of recesses for accommodating the first adhesive layer. The pellicle frame is adhered with the photo mask through the first adhesive layer accommodated in the plurality of recesses. The pellicle is disposed on the pellicle frame. The pellicle frame is between the pellicle and the first adhesive layer. An optical apparatus including the above-mentioned photo mask assembly is also provided.