Electron beam irradiation method and scanning electronic microscope

A scanning electron microscope comprising:

• an electron source;
• a lens that converges an electron beam emitted from the electron source, and
• a deflector that deflects an irradiation position of an electron beam, the deflector comprising
• a controller that controls the deflector, the controller controlling the deflector so that a sample is irradiated with a first electron beam to charge a sample and scanning of a second electron beam onto the charged sample is performed, wherein:
• the controller controls the deflector so that:
• the first electron beam is irradiated to a first position and a second position, the first position and the second position being symmetrically arranged with a pattern center of a hole pattern formed on the sample as a point of symmetry, the first position and the second position being arranged outside the hole pattern,
• the first electron beam is further irradiated after then to two middle positions located between the first and second positions already irradiated by the first electron beam, and on a circumference of a circle defined by the first and second positions with the point of symmetry as a center, and
• irradiations of the first electron beam to middle positions on the circumference of the circle between positions already scanned by the first electron beam is thereafter repeated further in a manner that the first electron beam is deflected so as to be selectively irradiated on an area outside the hole pattern.