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:
Jan. 17, 1995
Filed:
Mar. 13, 1992
Michael Cresswell, Frederick, MD (US);
Richard Allen, Germantown, MD (US);
Loren Linholm, Ijamsville, MD (US);
Michael Gaitan, Gaithersburg, MD (US);
The United States of America as represented by the Secretary of Commerce, Washington, DC (US);
Abstract
A test structure for submicrometer metrology as used in integrated circuit manufacture comprises a bridge conductor divided into three segments by pairs of voltage taps. A first segment has no intermediate taps; a second segment has a number of dummy taps intermediate its ends; and a third segment has a single central tap, which may typically be formed in a different step than the remainder of the test structure, intermediate its ends. Preferably, the central tap extends from the same side of the bridge conductor as the taps at the ends of the third segment thereof. In order to evaluate a manufacturing operation, for example, to monitor the accuracy of registration of successive manufacturing steps, test signals are applied successively between the pairs of pads. Comparison of the response of the first and second segments to the test signals allows evaluation of the segment shortening effect of the taps; comparison of the response of the two portions of the third segment to the test signals allows evaluation of their lengths, and thus of the accuracy of registration of the step used to form the central tap.