| 摘要 |
In a scanning electron microscope microcolumn which may be used in inspection of articles, a target is used to convert secondary electrons emitted by the specimen into tertiary electrons. These tertiary electrons are then detected by a conventional electron detector. Because the shape and dimensions of the target are relatively unconstrained in comparison with the shape and dimensions of the electron detector, an effective detection of the secondaries passing close to the optical axis of the apparatus can be achieved. The shape and material of the target may be chosen to optimize the detection efficiency of the system. |
