Transmission electron microscope and operation method thereof

A transmission electron microscope comprising:

• a beam irradiation provider;
• a first lens system provided with respect to the beam irradiation provider;
• a holder provided with respect to the first lens system and configured to mount a sample;
• a second lens system provided with respect to the holder;
• a detection mechanism provided with respect to the second lens system;
• a controller,
• wherein the detection mechanism includes:
• a scintillator configured to detect an electron beam;
• a light propagation unit through which light converted in the scintillator propagates;
• and
• an imaging element configured to receive the light propagating through the light propagation unit;
• and
• a film provided between the second lens system and the detection mechanism and configured to reduce an amount of electrons incident on the detection mechanism,
• wherein a diffraction pattern is acquirable using the detection mechanism in a state where the film overlaps with a center spot.

A method for operating a transmission electron microscope, the method comprising:

• increasing a liquid crystal control voltage applied to a first liquid crystal cell and a second liquid crystal cell of a liquid crystal panel;
• storing, in a memory, characteristic information indicating a relationship between the liquid crystal control voltage and transmittance, when obtaining data within a dynamic range in each of the first liquid crystal cell and the second liquid crystal cell;
• providing irradiation based on the stored liquid crystal control voltage;
• generating first light intensity data after attenuation based on the stored liquid crystal control voltage;
• and
• calculating second light intensity data before attenuation corresponding to an intensity of received light from the first light intensity data based on the characteristic information.

An operation method of a transmission electron microscope, the method comprising:

• designating an observation area on a sample and setting an exposure time;
• acquiring a diffraction pattern in a detection mechanism by irradiating the sample with an electron beam;
• placing a film at a position corresponding to a center spot;
• acquiring the diffraction pattern in the detection mechanism by irradiating the sample with the electron beam;
• and
• determining whether a signal intensity obtained in the detection mechanism is 90% or more of a specific upper limit value, and when the signal intensity is less than 90%, extending the exposure time, and when the signal intensity is 90% or more, acquiring the diffraction pattern in the extended exposure time.