公开(公告)号：DE2860442D1

公开(公告)日：1981-02-26

申请号：DE2860442

申请日：1978-11-10

Applicant: IBM

Inventor： SHEA VINCENT ,  WOJCIK WALTER JOSEPH

IPC: G03F1/62 ,  G03F7/20 ,  H01L21/027 ,  G03B41/00 ,  G03F1/00 ,  G03F7/26

Abstract: In a projection printing system the pattern mask, whose image is projected onto a light sensitive layer, is protected with a thin, 0.2-6 micron thick, transparent film or pellicle which is positioned an optically large distance of about 1-125 mm from the mask surface by a spacer member. Any dirt particles on the surface of the pellicle will be out of focus and are not printed in the light sensitive layer. A pellicle can also be employed to protect the light sensitive layer at the image plane.