Apreo SEM FAQ's
Do I need to insert the GAD detector before I switch to low-vacuum mode?
Low-vacuum mode is accessible without any accessory mounted. The accessible pressure range will be up to 50 Pa. With a pressure limiting aperture (PLA) such as the Gaseous Analytical Detector (GAD), the results will further improve. Moreover, with the GAD, pressures up to 500 Pa are possible.
What does "optional" mean for the immersion lens?
The immersion lens is not required when configuring the system and it is also not required to use if installed. The Apreo SEM achieves a resolution of 1.3 nm at 1 kV. With the immersion lens installed and excited, this improves to 1.0 nm at 1 kV. On top of this, additional compound lens filtering capabilities are available.
Can you use immersion while the electrostatic column is off?
In principle, no. The best results are obtained with both the acceleration tube and immersion lens on. There is no clear use case for immersion only. By default, the Apreo SEM operates with the acceleration tube on, and immersion is switched on when required.
Do the in-column detectors (T1, T2, T3) work at TV rate?
Yes, they do.
You're saying beam deceleration is not possible on a tilted sample. Why is that?
Beam deceleration (BD) creates an electrostatic field between the sample and the pole piece. With a tilted sample, the field lines will be at an angle, and this introduces stigmation in the image. This also happens for samples with large topographic features. As a result, even though BD is a very useful feature and comes standard on the Apreo SEM, it cannot be used 100% of the time. Therefore, the Apreo SEM does not rely on BD to achieve its resolution. The no-BD resolution is 1.0 nm at 1 kV for the immersion system and 1.3 nm at 1 kV without immersion lens.
How much does the Apreo SEM cost?
Never before has access to this level of performance and versatility been available in one product at a very attainable price. Please
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