Patent attributes
There is provided an electron-beam calibration technology whereby deflection calibration used in the electron-beam system can be performed with a high accuracy. A one-dimensional diffraction grating is located such that direction of the grating becomes parallel to an electron-beam scanning direction. Next, the electron-beam scanning is horizontally performed while displacing the electron-beam scanning in the perpendicular direction so that the electron-beam scanning displacement quantity will coincide with pitch size of the grating. From a secondary-electron signal image acquired, based on the presence or absence of moiré interference fringes, it can be judged whether or not the deflection calibration in the direction perpendicular to the electron-beam scanning has been correctly performed.