US 6,982,134 B2
Multiple stepped aperture repair of transparent photomask substrates
Cheng-Ming Lin, Hsin-Chu (Taiwan)
Assigned to Taiwan Semiconductor Manufacturing, Co., LTD,
Filed on Mar. 28, 2003, as Appl. No. 10/402,196.
Prior Publication US 2004/0191642 A1, Sep. 30, 2004
Int. Cl. G01F 9/00 (2006.01); G03C 5/00 (2006.01)
U.S. Cl. 430—5 19 Claims
OG exemplary drawing
 
1. A method for repairing a photomask comprising:
providing a transparent photomask substrate having a defect formed within the transparent photomask substrate; and
forming into the transparent photomask substrate a multi-stepped aperture which eliminates the defect, the multi-stepped aperture having a series of progressive steps which separate a series of progressive plateaus, each plateau having a plateau width and step height such as to enhance transparent photomask substrate transmittance within the multi-stepped aperture.