Imaging Hard Surface Photomask Blanks Using White Light Actinic Radiation
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
A hard surface photomask blank typically consists of a glass base coated with a thin film (.1000 Ao) of metal, metallic oxide, or semiconductor. Typical thin film coatings include chromium, iron oxide, and silicon. In order to image a hard surface photomask blank, it is coated with a photosensitive material and selectively exposed to the required actinic radiation. The photosensitive coating is then subjected to a developing solution which removes the exposed areas of the photosensitive coating, thereby leaving the underlying thin film coating unprotected from contact with etchant solutions. These unprotected areas of the thin film are then removed by subjecting the blank to the appropriate etchant. Finally, the remaining photosensitive coating is stripped to yield the finished photomask.