Semiconductor device test method and semiconductor device tester
A defective position of a sample to be tested is detected by irradiating the test sample and another test sample with electron beam while scanning the test samples, storing values of current generated in the test samples correspondingly to electron beam irradiation positions as current waveforms and comparing the current waveforms.
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.
2. The method of claim 1 wherein comparing the first location and the second location includes comparing amplitudes of the first current waveform with amplitudes of the second current waveform.
3. The method of claim 2 wherein measuring the first current waveform includes measuring the magnitude and polarity of the first current waveform.
4. The method of claim 1 wherein the electron beam has a rectangular cross-section.
5. The method of claim 1 wherein the electron beam has a width that is less than the contact or via hole in the first area.
6. The method of claim 1 wherein the electron beam has a circular cross-section.
7. The method of claim 1 further comprising displaying bit map information indicative of the first location.
8. The method of claim 1 further comprising:
comparing the difference between the first location and the second location with a predetermined value; and
detecting a defect in at least one of the contact or via hole in the first area and the contact or via hole in the second area when the difference is greater than the predetermined value.
9. A method of testing a semiconductor wafer having first and second areas, each of which includes a plurality of contacts or via holes which are arranged in the same or substantially the same pattern, 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 contacts or via holes 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 the scanning of the electron beam across the second area, while obtaining second coordinates information indicative of irradiating positions of the electron beam in the second area;
determining a second location of the contacts or via holes 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.
10. The method of claim 9 wherein comparing the first location and the second location includes comparing amplitudes of the first current waveform with amplitudes of the second current waveform.
11. The method of claim 9 wherein the electron beam has a rectangular cross-section.
12. The method of claim 9 wherein the electron beam has a width that is less than at least one of the contacts or via holes in the first area.
13. The method of claim 9 wherein the electron beam has a circular cross-section.
14. The method of claim 9 further comprising displaying first bit map information indicative of the first location.
15. The method of claim 14 further comprising displaying second bit map information indicative of the second location.
16. The method of claim 9 further comprising:
comparing the difference between the first location and the second location with a predetermined value; and
detecting a defect in at least one of the contacts or via holes in the first area and the contacts or via holes in the second area when the difference is greater than the predetermined value.