Patent ID: 7142313
Filing Date: 2006-11-28
Classification: G01B

Abstract:
1. An interaxis angle correction method for an apparatus including a table that linearly translates in a reference plane along a translation axis which should form a desired angle at the reference plane with respect to a reference line provided on the reference plane, and a sensor having the reference line provided on the reference plane as an axis of measurement, for acquiring measurement-axis-direction position information on a sample located on the table, the method correcting an error in an angle formed by the measurement axis and the translation axis, and comprising: a reference sphere measurement step of scanning, with the sensor, a reference sphere located on the table of the apparatus, in the measurement-axis direction at a designated translation-axis-direction position on the reference sphere to acquire measurement-axis-direction contour information, and performing the scanning and acquisition at a plurality of different designated translation-axis-direction positions on the same reference sphere, with the table being linearly translated; a peak detection step of detecting a peak point in the measurement-axis-direction contour information acquired in the reference sphere measurement step, and performing the detection for each set of measurement-axis-direction contour information acquired in the reference sphere measurement step; an error information acquisition step of determining an actual straight line representing an actual direction of motion of the table based on position information of each peak point detected in the peak detection step, and obtaining information related to the inclination of the actual straight line with respect to an ideal straight line representing an ideal direction of motion of the table; a correction information acquisition step of obtaining correction information for correcting a measurement error related to the position in the measurement-axis direction, caused by the inclination of the actual straight line determined in the error information acquisition step; and a correction step of correcting the measurement-axis-direction position information obtained from the sensor, based on the correction information obtained in the correction information acquisition step.