Patent ID: 7420379
Filing Date: 2008-09-02
Classification: G01R

Abstract:
1. A method of testing a semiconductor wafer having first and second areas, each of which includes at least one contact or via hole, the method comprising: scanning an electron beam across the first area; measuring a first current waveform generated in response to the scanning of the electron beam across the first area, while obtaining first coordinates information indicative of irradiating positions of the electron beam in the first area; determining a first location of the contact or via hole in the first area using the first current waveform and the first coordinates information; scanning an electron beam across the second area; measuring a second current waveform generated in response to scanning the electron beam across the second area, while obtaining second coordinates information indicative of irradiating positions of the electron beam in the second area; and determining a second location of the contact or via hole in the second area using the second current waveform and the second coordinates information; and comparing the first location and the second location to detect a difference therebetween.