Multilevel Chromium Mask Repair Process for Clear Defects
Original Publication Date: 1986-Aug-01
Included in the Prior Art Database: 2005-Mar-09
Blanket chromium (Cr) films on transparent substrates intended for use as photomasks frequently have clear defects (regions where no Cr or thin Cr exists). A process is described for repairing these defects. The figure shows a transparent substrate 2 having a Cr film overlayer 4. Note the clear defect region d, (i.e., a region initially devoid of Cr). An organic layer 6 is deposited on the Cr layer 4, and is overlayed with a continuous film 8 of an inorganic material. Next, positive photoresist (not shown) is applied on the organic film 8. The positive photoresist is then exposed by light passing upward through the transparent substrate 2, the clear defect d, and the transparent film layers 6 and 8.