Method for the preparation of a frame-supported pellicle for photolithography

摘要

A process for the preparation of a frame-supported pellicle membrane used for dust-proof protection of a photomask in the photolithographic patterning work of, for example, semiconductor devices. An improvement is proposed for trimming of a pellicle membrane formed on a base plate and adhesively bonded to a pellicle frame to remove the extraneous portion of the membrane protruded out of the pellicle frame. Instead of the mechanical punching method for trimming, the trimming work according to the invention is performed by using a cutting device having a cutter element heated at a temperature higher than the melting point of the thermoplastic resin forming the membrane so that the membrane is trimmed by melting of the resin. Different from the conventional mechanical punching method, the trimming process of the invention is free from the problem of occurrence of dust particles deposited on the membrane to adversely affect the quality of the pattern reproduction.