Patent ID: 8530836

Claim:
An electron-beam dimension measuring apparatus comprising: electron-beam irradiating means for irradiating a surface of a sample with an electron beam; a stage on which the sample is placed; a photoelectron generating electrode disposed so as to face the sample; ultraviolet light irradiating means for emitting ultraviolet light; and control means controls operations of: measuring a dimension of a calibration sample of known dimension by irradiating the electron beam thereon where the calibration sample is grounded so that its surface potential is 0 V, causing the ultraviolet light irradiating means to irradiate both the sample and the photoelectron generating electrode with the ultraviolet light at the same time for a predetermined length of time, to cause the sample and the photoelectron generating electrode to emit photoelectrons, measuring a dimension of the sample by irradiating the electron beam thereon, applying a voltage to the photoelectron generating electrode in such a way that the measured dimension of the sample becomes identical to or within a predetermined difference from the measured dimension of the calibration sample, where the voltage differs from 0 V by a difference between energy of photoelectrons emitted by the sample and energy of photoelectrons emitted by the photoelectron generating electrode, and thereby controlling an electric potential of the surface of the sample to 0 V.