| 摘要 |
PURPOSE:To make it possible to accurately measure a dimension even if an article to be measured is curved, by detecting the deflection angle of electron beam with respect to the article to be measured and the position of the article to be measured on an optical axis and calculating an actual working distance from these detected values. CONSTITUTION:The electron beam deflection angle to a semiconductive wafer being an article to be measured is detected by the dimension detection part 20 arranged to the surface of the wafer 1. The position of the wafer 1 on an optical axis is detected by the position detection part 30 arranged to the back surface of the wafer 1 in opposed relation to the dimension detection part 20. An actual working distance is calculated in an operation part 40 on the basis of the detected values of the dimension detection part 20 and the position detection part 30 and the dimension of the pattern 1a on the surface of the wafer 1 is further accurately calculated on the basis of said working distance. By this method, even when the wafer 1 is curved, the dimension of the wafer 1 can be measured with high accuracy. |
