SAMPLE STAGE AND PARTICLE SIZE-MEASURING APPARATUS USING THE SAMPLE STAGE

摘要

PROBLEM TO BE SOLVED: To correctly readjust an up-down positional deviation of a face to be measured by moving a sample-holding plate so that the position information obtained by a position determination means becomes a predetermined true position. ;SOLUTION: When an angle of a face to be measured is shifted from when an optimum focal position is set, two keen position detectors PSD 142, 144 are arranged so as to correctly obtain a positional information. A position is determined with taking into consideration an angle information of the face to be measured which is obtained from an output voltage difference C of the detectors. The obtained angle information is compared by a CPU 246 with the angle when the optimum focal position is set. When the obtained angle information is judged to be shifted from a predetermined angle, a position of the face to be measured when regularly reflecting is estimated from the angle information and an output voltage A of the PSD 142, and set as a true position of the face to be measured. On the contrary, when the angle information is judged not to contain errors, a temporary position information is set as a true position information. The obtained position information and the position information when the optimum focal position is set are compared by the CPU 246. If the obtained position information is judged to error, a control circuit 138 makes a rectangular movement means 148 move a sample-holding plate 128 in a Z direction so that the position information determined by the CPU 246 becomes the optimum focal position.;COPYRIGHT: (C)1999,JPO