| 摘要 |
PURPOSE:To form a correct attenuation waveform of a current by integrating a carrier current induced in a sample due to repeating radiation of charged particle beam and concurrently varying little by little the term from stopping irradiation to starting integration. CONSTITUTION:A carrier current is induced by radiating the electron beam EB to a sample 7, the attenuated waveform is recorded, and the inspection for a semiconductor is achieved by measuring the time at which the current increases to a predetermined value. In this case, a blanking signal generating circuit 5 is controlled by an operation processor 11 to repeatedly radiating the beam to the sample 7. A generated carrier current is integrated by an integration amplifier 8 and the time (t) from stopping radiation to starting integration is varied little by little by a switch signal generating circuit 13 to evaluate the changing rate of a signal indicating the integrated value S(t). Thereby, the waveform distortion is reduced and a correct attenuated waveform can be obtained even when the life of the carrier current is short. |
