| 摘要 |
PURPOSE:To accurately find the mean line width of a pattern by finding the correlation between the output waveform of a charged particle ray scanned on the pattern of a base and signal waveforms obtained by measuring previously various reference samples whose pattern line widths are already known. CONSTITUTION:The pattern 2 formed on the base 1 is irradiated with the charged particle ray 3 and reflected charged particles 4 exiting from the pattern 2 are detected by a detector 5. Then, an output waveform shown in a figure is obtained from the detector corresponding to time variation. When the scanning speed of the charged particle ray 3 is denoted as S and the position of the scanning start point is denoted as Xo, the relation between the time (t) after the scanning start and the position X is expressed by X=Xo+St. Further, the width of the pattern 2 is represented by the mean line width of the width of the surface and the width that the pattern 2 contacts the base 2 to. Reference samples which are variously different in pattern width as to the material of the base 1 and the material of the pattern 2 are prepared. Then, the statistical correlation between the output signal waveform of the detector 5 and signal waveforms at the time of various mean line widths which are already known by measuring the reference materials is found, so that the maximum mean line width when the coefficient of the correlation is maximum is the mean line width of the pattern 2.
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