Secondary electron detector using a conductive ultra-thin membrane provided in an atmospheric pressure electron microscope

A secondary electron detector of an atmospheric pressure electron microscope for detecting a secondary electron generated from a sample (S), the secondary electron detector comprising:

• a substrate (101) installed at a lower end of a column (10) of the atmospheric pressure electron microscope, and a through-hole part (102) is formed in a center of the substrate (101) through which a high-energy electron beam passes;
• a second thin membrane (120) attached to a front surface of the substrate (101) to cover the through-hole part (102), and having a plurality of through holes (121) formed therein;
• and,
• a first thin membrane (110) installed on the second thin membrane (120) to hermetically seal the through holes (121), and blocks air so that a high vacuum inside the column (10) is maintained, but allows the high-energy electron beam to pass through, and can capture low-energy secondary electrons, and is electrically conductive, and is thinner than the second thin membrane (120);
• wherein a voltage (Vb) is applied between the first thin membrane (110) and the sample (S), and a positive voltage is connected to the first thin membrane (110),
• wherein the secondary electrons generated when the electron beam is irradiated to the sample (S) are captured by the first thin membrane (110), and an ion charge is generated and amplified between the first thin membrane (110) and the sample (S) by the avalanche effect to generate a large current flow, and the current is displayed as an image of the sample (S) on a display unit.