Method of Producing Defect-Free Transmission Masks
Original Publication Date: 1985-Jan-01
Included in the Prior Art Database: 2005-Feb-18
The subsequently described method permits repairing defective transmission masks which, in addition to the desired openings, may have, for example, frayed openings and/or additional defect holes. Initially, all holes of the defective mask are closed and, subsequently, only the desired openings are opened. For that purpose, two identically structured transmission masks are used, whose defect holes are, however, in other regions than those of the mask to be repaired. Also required is a high-resolution exposure set-up. In the described example, an about 1 to 2 mm thick photoresist layer 2 is spun onto the top side of a defective silicon transmission mask 1 (Fig. 1A) comprising, in addition to the desired openings la, frayed openings lb and defect holes lc.