| 摘要 |
PURPOSE:To maintain the flatness of the surface of a pellicle and to enhance the accuracy of detection of foreign matter at the time of inspection by piercing an opening in at least a part of a pellicle frame for fitting the pellicle to a photomask and by making the opening closable with a tape. CONSTITUTION:A pellicle 12 is a transparent thin film of nitrocellulose and is fixed through a pellicle frame 13 of an Al alloy, etc., so that a reticle (photomask) 11 is covered with the pellicle 12 at a certain interval to protect a pattern part on the reticle 11. An opening 14 of a small diameter is pierced in one side of the frame 13 and a tape 15 having superior dust-tightness is stuck so as to close the opening 14. A part 16 of the tape 15 is not stuck to facilitate stripping. Since air permeability is rendered to an airtight chamber formed by the pellicle 12, the pellicle frame 13 and the reticle 11, the deformation of the surface of the pellicle 12 due to the difference between the internal and external pressures of the airtight chamber is prevented. The flatness of the surface of the pellicle is maintained and the accuracy of detection of foreign matter at the time of inspection is enhanced. |
