The inlens detector is perpendicular to the sample surface in the electro-optical path. This implies that it can only be used efficiently at low voltages up to 20 kV. In this range the suction of the so called beambooster has a very high yield of electrons. This allows a faster and gentler image generation comparing it with other detectors, especially at very low voltages. Its almost pure detections of secondary electrons allows a very close to the surface image that contains only little information from the bulk phase.
At first the name won’t let you suspect it, but the SE2 detector captures a combination of secondary (SE) and back-scattered (BE) electrons. Compared to the inles detector the image information originates from a greater average sample depth. The SE2 detector distinguishes itself from other detectors because of it’s position inside the machine. By his side mounting to the chamber wall, it gives much better topographical information than other detectors. The lower yield of electrons can be compensated by tilting the sample.
To meet the requirements of radiation-sensitive samples as well as the requirements of X-ray analytics, the NEON® 40 allows many options. Low voltage (0.1 to 5 kV) allows especially near surface images which are very low energetic and gentle. For analytical purposes the accelerating voltage can be increased up to 30 kV. Different apertures, different scanning methods and even an additional modulation of the electron optics (high current mode) extend the variety of intensities.
Besides the pure observation of the surface, different sample preparations offer the view into the sample beneath its surface: The cryofracture, the cross section and of course the FIB technology (see next section).
Table 1 SEM specific properties
|SEM resolution||1,1 nm @ 20 kV|
2,5 nm @ 1 kV
|SEM probe current||4 pA - 20 nA|
|SEM acceleration voltage ||0,1 - 30 kV|
|SEM emitter||Schottky field emitter|