| 摘要 |
PURPOSE:To increase the proportion of secondary electrons catched by a secondary- electron detector after developing from a test sample by providing a secondary-electron reflector, which is made of a conductive member and to which a negative electric potential is applied, on the opposite side to the said detector close to the sample. CONSTITUTION:A secondary-electron detector is installed close to a test sample 3, and a disk-like or semi-spherical shell-like conductive member 9 is installed on the opposite side to the detector. In addition, a negative electric potential is applied to the conductive member 9. As the result, secondary electrons developing from the sample 3 are efficiently taken into a scintillator 6 due to the electric field formed among the conductive member 9, the sample 3 and corona rings 5. Besides, secondary electrons discharged in the opposite direction of the detector, especially, can be very efficiently catched by the detector. A secondary-electron reflector consisting of the above conductive member 9 has a semi-spherical shell-like shape, and a small hole 10 is provided in the reflector so that the hole 10 is somewhat apart from the center of the reflector. The hole 10 is used for passing electrons before they become incident upon the sample 3. The reflector is prepared by coating a conductive or non-conductive plastic with a thin conductive film. |
