| 摘要 |
An apparatus for analyzing failures of an IC chip and locating defective portions by irradiating the surface of an IC with an ion beam and displaying a potential contrast image of a wiring conductor on the surface of the chip, which provides improved handling and better image quality. To this end, means for setting a plurality of patterns for stopping an updating operation of the patterns is provided in a test pattern generator, the pattern updating operation of the test pattern generator is stopped wherever this stop pattern is generated, and a stop signal is sent to an ion beam tester so as to acquire image data. When acquisition of the image data is completed, signal generation means transmits an acquisition completion signal, and the test pattern generator again starts the pattern updating operation. As a result, different test patterns can be applied alternately to the chip under test, and image quality can be improved by adding and subtracting the image data. A method of locating defective portions of the IC comprises turning off a power supply of the chip at the time of a first test pattern (r) so as to fix the logic of the wiring conductor at the (r) pattern to LOW so that a difference always occurs in a potential contrast image when any difference of the logic exists between acceptable and defective chips by the acquisition of the image data at the second test pattern (n).
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