| 摘要 |
<p>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 circuit. 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 evaluator circuit which controls the intensity of a display means, such as a picture screen.</p> |
