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:
Oct. 09, 2001
Filed:
Mar. 08, 1999
David Ziger, San Antonio, TX (US);
Pierre Leroux, San Antonio, TX (US);
Philips Semiconductor, Inc., Sunnyvale, CA (US);
Abstract
A semiconductor fabrication process permits for narrowing linewidths using Optical End of Line Metrology (OELM). OELM involves measuring relative line shortening effects that are inherent in many semiconductor fabrication processes using optical overlay instruments. According to one embodiment, the process involves a frame that has two adjacent sides which are constructed of lines and spaces. The frame is imaged onto a wafer, but the optical line measurements used to implement the frame over-predict actual shortening of the lines. To calibrate the optical line measurements to the physical implementation, corrections are determined to relate the optical measurements to the actual line shortening: a relationship between the narrow linewidth elements of varying line lengths using a representation and the narrow linewidth elements in a physical implementation of the representation, a pitch effect for the narrow linewidth elements when using the alignment tool, and a duty cycle effect reflecting the impact of the line-size/spacing of the lines in the grating. A processor then calibrates the optical aligning tool as a function of these factors.