| 摘要 |
PURPOSE:To detect signals under the respective optimum conditions of radiation for objects whose positions are to be detected, and detect signals under the best conditions also for a filament current, a spot diameter, etc., having an influence on the signals, by providing an electron beam optical equipment in which radiation conditions to irradiate a first and a second objects can be changed. CONSTITUTION:Electron beam optical equipments 13 and 14 measure electric signals 38-45 from a mask 10 and a wafer 11. Conditions of scanning and radiation of these equipments are controlled by an control equipment 15 of the electron beam optical system. The electron beam optical equipment is composed of a part 61 to generate an electron beam, a part 62 to set radiation conditions, a part 63 to control an scanning line, an electron beam transmitting part 64, and a part 65 which detects reflected electrons or the secondary electrons and converts it to an electric signal. As for radiation conditions, values of an acceleration high voltage, a filament current and a spot diameter are set, by changing the respective values of the acceleration high voltage, an alignment power source and a lens power source. Thereby, signals can be detected under the optimum condition. Further, signals can be detected under the optimum condition with respect to causes having an influence of the signals.
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