The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 20, 2007
Filed:
Jul. 10, 2003
Francesco Cerrina, Madison, WI (US);
Adam Pawloski, San Jose, CA (US);
Lin Wang, Baton Rouge, LA (US);
Francesco Cerrina, Madison, WI (US);
Adam Pawloski, San Jose, CA (US);
Lin Wang, Baton Rouge, LA (US);
Wisconsin Alumni Research Foundation, Madison, WI (US);
Abstract
A dark-field imaging method for detecting defects in reflective lithography masks (e.g., extreme ultraviolet (EUV) masks) used, e.g., in processes for the fabrication of microelectronic devices. A mask blank is coated with a photoresist layer having a fluorescent dye incorporated therein. The photoresist layer is exposed to a source of radiation (e.g., EUV radiation or glancing soft X-rays). In areas of the mask blank having defects the combined direct and reflected radiation will be insufficient fully to expose the photoresist layer. After development, photoresist will remain on the mask blank surface in areas corresponding to defects. Illumination with the excitation wavelength of the fluorescent dye reveals the location of any remaining photoresist, which can be detected using an optical microscope, thereby to detect defects in the mask blank.