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:
Apr. 11, 1989
Filed:
Dec. 15, 1986
Hans D Brust, Dudweiler, DE;
Siemens Aktiengesellschaft, Berlin and Munich, DE;
Abstract
A method for function checking microelectronic components inside LSI circuits, particularly during the development phase, provides localization and imaging of regions of a specimen which carry defined signals that depend on the operating status of the cirucit. For localizing the points carrying the defined electrical signals, a primary beam reads the signal at the measuring point and a secondary signal derived therefrom is compared in a detector arrangement to the anticipated or sought-after signal by a correlation method. For the correlation, the intensity of the primary beam or the current of the secondary particles are modulated alternately with the sought-after or anticipated signal and, respectively, with the negation of the sought-after or anticipated signal and the measured secondary signal is integrated. Part of the integrated secondary signal changes with the frequency prescribed by the signal change, which is filtered out and supplied to an evalutor circuit which controls the intensity of a display, such as a picture screen.