Scanning electron microscope and specimen observation method

A scanning electron microscope, comprising:

• an electron source;
• an objective lens configured to focus a primary electron beam emitted from the electron source on a specimen;
• a deflector configured to deflect, using at least an electric field, an electron between the electron source and the objective lens;
• a stage where the specimen is placed;
• a power supply configured to apply, to the stage, a voltage for decelerating the primary electron beam;
• a detector configured to detect an electron;
• and
• a control apparatus, wherein
• the deflector includes an electron conversion electrode provided to collide with a secondary electron emitted from the specimen due to emission of the primary electron beam, a beam guide that penetrates the electron conversion electrode and through which the primary electron beam passes, and a first electrode and a second electrode facing each other and allowing transmission of an electron therethrough,
• the detector detects a tertiary electron that is emitted due to collision of the secondary electron emitted from the specimen with the electron conversion electrode or a specimen-side end surface of the beam guide and that is transmitted through the first electrode,
• the electron conversion electrode is switchable independently between positive voltage application and negative voltage application or a ground potential,
• the deflector includes a fourth electrode facing the electron conversion electrode and allowing transmission of an electron therethrough, and
• the fourth electrode is set to the ground potential and is provided at a same height as the specimen-side end surface of the beam guide or closer to the electron conversion electrode.

A specimen observation method using a scanning electron microscope, wherein

• the scanning electron microscope includes:
• an electron source;
• an objective lens configured to focus a primary electron beam emitted from the electron source on a specimen;
• a deflector configured to deflect, using at least an electric field, an electron between the electron source and the objective lens;
• a stage where the specimen is placed;
• a power supply configured to apply, to the stage, a voltage for decelerating the primary electron beam;
• a detector configured to detect an electron;
• and a control apparatus,
• the deflector includes an electron conversion electrode provided to collide with a secondary electron emitted from the specimen due to emission of the primary electron beam, a first electrode and a second electrode facing each other and allowing transmission of an electron therethrough, and a third electrode facing the first electrode with the second electrode interposed therebetween,
• the detector detects a tertiary electron that is emitted due to collision of the secondary electron emitted from the specimen with the electron conversion electrode and that is transmitted through the first electrode,
• the electron conversion electrode is segmented into a plurality of segmented electrodes, and
• the control apparatus causes a potential of the third electrode to have a positive potential difference relative to a potential of the second electrode.