Patent ID: 6083577
Filing Date: 2000-07-04
Classification: G03F,Y10T

Abstract:
A mask protective device comprising a frame, the size of which is set to surround a mask pattern, and a transparent thin film put on said frame to close one opening of said frame, said mask protective device further comprising:string-like beading which is formed all around an end face at the other opening of said frame by linearly applying adhesives or pressure-sensitive adhesives for bonding said frame of said mask protective device to a mask surface; and a curved groove formed on the end face of said frame by portions of said string-like beading facing each other in such a manner that said portions of said string-like beading constitute the side walls of said curved groove, wherein said curved groove has one opening communicating with the outside of said mask protective device and the other opening communicating with the inside of said mask protective device, and when said mask protective device is mounted on said mask surface, the mask surface comes into contact with the top of said string-like beading so that said groove becomes an air passage;wherein said curved groove is formed by applying adhesives or pressure-sensitive adhesives all around the end face at the other opening of said frame in such a manner as to form said string-like beading as at least two string-like beads, arranged inside and outside on the end face, having respective discontinuities which are formed in different places on the end face of said frame to form openings of said groove for allowing communication between the inside and the outside of said frame.