| 摘要 |
PURPOSE:To minimize the effect of noises, and increase the contrast of a scanning electron microscope by making signals of a transmitted-electron detector which have great variations to be amplified greatly, and by making signals of the detector which have small variations amplified to a small extent. CONSTITUTION:Electrons transmitted by a sample 5 are detected by a transmitted- electron detector 8B, while electrons diffracted within the sample 5 are detected by a diffracted-electron detector 8D. Signals sent from the detector 8B are supplied to the drain of a field-effect transistor 10 through an amplifier 9 and a resistance R1, in that order. Signals sent from the detector 8D are supplied to the gate of the transistor 10 through an amplifier 11. Signals of the detector B which vary greatly are amplifed to a great extent, while signals of the detector B which vary a little are amplified to a small extent. After that, the signals of the detector B are supplied as brilliance-modulation signals, through an operational smplifier 12 to a cathode ray tube 13. |
