| 摘要 |
PURPOSE:To obtain an equal quantity of secondary electron signals and increase measuring accuracy, by providing a programmable counter, dividing the frequency of a synchronous signal of a tester supplying a test signal to a measured sample and controlling scanning of X and Y-axis scanning coils. CONSTITUTION:An electron microscope 11 is equipped with a beam pulse generator 12, and a tester 14 supplies a test signal to a measured sample 13. To generate an electron beam corresponding to a synchronous signal supplied from the tester 14, a beam pulse generator circuit 15 controls the generator 12. A secondary electron detector 16 detects a secondary electron from the sample 13 to give the electron to a CRT17. A synchronous signal output from the tester 14 is frequency divided by a programmable counter 23 and supplied to a D/A converter 18, and a scanning control signal output from the converter 18 is fed to an X-axis scanning coil 19 while a D/A converter 20 is controlled through a divider circuit 22. An output of the converter 20 is fed to a Y-axis scanning coil 21. A quantity of the secondary electron signal obtained in such way is equalized, and voltage measuring accuracy can be improved. |
