LiteScope Integration into SEM: From Adaptation Plate to Correlative Measurement

Correlative AFM-in-SEM analysis only works in practice if the AFM can be brought into the electron microscope without turning every measurement into an engineering project. LiteScope was designed around that requirement. It mounts on the existing SEM stage, uses the microscope's own vacuum feedthrough and is controlled from the same PC as the SEM. No modification of the microscope itself is needed, and the SEM can be returned to its standard configuration at any time.

Why put the AFM inside the SEM

SEM and AFM answer different questions about the same surface. The SEM offers fast navigation over large areas, high lateral resolution and, with EDS or EBSD, compositional and crystallographic contrast. The AFM adds what electron imaging cannot deliver: true quantitative height, roughness, and local mechanical, electrical and magnetic properties.

Running both techniques ex situ means transferring the sample between instruments, exposing it to air and searching again for the same region of interest. With the AFM inside the SEM chamber, the tip is placed on the feature selected in the SEM image, both datasets are acquired in the same vacuum and at the same spot, and air-sensitive or beam-modified samples stay under controlled conditions from start to finish.

What makes the integration possible

A conventional AFM relies on a laser beam reflected from the cantilever to detect its deflection. That optical path takes up space that simply is not available between the SEM pole piece, detectors and stage. LiteScope works with self-sensing probes, which read out the cantilever deflection electrically, so no laser or optical alignment is required. The result is a compact, low-profile scanner that fits into the chamber of a standard SEM and leaves the electron column and detectors free to operate.

Integration scheme: LiteScope is fixed to an adaptation plate on the SEM stage interface and connected through a vacuum feedthrough to the NenoBox control unit.

The hardware chain

The whole system consists of four elements:

• Adaptation plate and SEM stage interface that match the stage of the specific microscope model.
• LiteScope scanner, attached to the adaptation plate with four screws.
• Vacuum feedthrough that carries the signal and drive cables out of the chamber. Adapters and feedthroughs are supplied for the given SEM and can be customized to the client's requirements.
• NenoBox control unit, connected to the same PC that controls the SEM.

Installation step by step

1. Open the chamber. The SEM is vented and the stage is accessed in the usual way, exactly as for a standard sample exchange.

2. Mount the adaptation plate. The adaptation plate is screwed onto the SEM stage interface. It is made for the particular stage, so the AFM sits in a defined position relative to the electron beam.

3. Attach LiteScope and connect the cables. LiteScope is fixed to the plate with four screws and its cables are plugged into the prepared vacuum feedthrough inside the chamber.

4. Check the position and close the chamber. LiteScope now sits on the SEM stage below the pole piece. After loading the sample and probe, the chamber is closed and pumped down as usual.

5. Work with the SEM stage as usual. Because LiteScope travels with the SEM stage, the microscope's own stage movements are used to bring the region of interest under the beam and the tip. The SEM keeps its full imaging and analytical capabilities during the AFM measurement.

Mounting, and later dismounting, the complete setup takes just a few minutes and can be done by any trained SEM user. No service visit is needed to switch between AFM-in-SEM work and standard SEM operation.

One workstation, one software

LiteScope is operated through NenoView software running on the same PC as the SEM. The SEM image is used to navigate the tip to the region of interest, and the AFM scan is then run on exactly that spot. With CPEM (Correlative Probe and Electron Microscopy), AFM and SEM signals are acquired simultaneously in the same coordinate system, so topography, material contrast and other channels can be overlaid without any manual image registration.

Which SEMs are compatible

Thanks to its compact design, LiteScope is compatible with most existing SEMs and FIB-SEMs from Hitachi, JEOL, TESCAN, Thermo Fisher Scientific and ZEISS. Adapters and feedthroughs are prepared for the specific microscope model, and non-standard configurations can be solved individually.

Not sure whether LiteScope fits your microscope? Send us your SEM model and we will check the compatibility for you.

SEM integration and compatibility