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:
May. 06, 2003
Filed:
May. 16, 2000
Paul S. Davids, Portland, OR (US);
Intel Corporation, Santa Clara, CA (US);
Abstract
The present invention comprises a tool for and a method of inspecting a mask used in photolithography to determine errors in phase, amplitude, and pattern edges. An embodiment of the tool comprises a laser source, a polarizing beam splitter, a first shutter, a mask, a second shutter, a quarter wave retarder, a single-mode optical fiber, and a CCD detector array. An embodiment of the method comprises four independent measurements of light intensity, comprising: a pattern of a mask, a diffraction pattern of a reference pinhole, an interference pattern of the mask and the reference pinhole, and an interference pattern of the mask and the reference pinhole with a known phase difference. Calculations are performed to determine phase and amplitude information as a function of location on the mask. The phase and amplitude information is then compared with a design layout of the mask to determine pattern edge information and identify possible defects in the mask.