Electron beam irradiation apparatus, electron beam exposure apparatus, and defect detection method

A defect detection method of detecting a defect of a backscattered electron detector, comprising steps of:

• detecting backscattered electrons by a plurality of backscattered electron detectors, the backscattered electrons being generated when an electron beam is irradiated on the mark;
• attenuating signal values indicating quantity of backscattered electrons detected by the plurality of backscattered electron detectors;
• and
• detecting a defect of the plurality of backscattered electron detectors based on attenuated signal values, with attenuation factors in said attenuation step being varied.

An electron beam exposure apparatus for exposing a pattern on a wafer by an electron beam, comprising:

• an electron beam generating section for generating an electron beam;
• a plurality of backscattered electron detectors for detecting backscattered electrons generated when the electron beam is irradiated on a mark;
• a plurality of attenuation sections for attenuating signal values indicating quantity of backscattered electrons detected by said plurality of backscattered electron detectors;
• and
• a defect detecting section for detecting a defect of said plurality of backscattered electron detectors by varying attenuation factors for said plurality of attenuation sections.