Beam teleportation for precision dose control in scanning transmission electron microscopy

Spatiotemporal dose control utilizing custom, vectorized scan trajectories in scanning transmission electron microscopy can be used to reduce image artifacts, mitigate beam-induced damage, minimize electrostatic charging, and enable the precise manipulation of sample structure. However, the inductance of the magnetic deflectors in the scan system induces an effective inertia of the beam spot, causing unintended exposure between target scan points ("beam dragging") and reduced dwell time at the target scan points ("beam lagging"). Using a fast electrostatic beam blanker synchronized with the scan controller to blank during inter-pixel transients, it is possible to "teleport" the beam spot between scan points, reducing or eliminating the extra dose and image background associated with deflector settling. We demonstrate this method on randomized scan patterns which are strongly affected by beam spot inertia. We show that background from the beam lagging can be discarded to simultaneously decrease dose and noise. As a result, this work opens up new possibilities for dose-rate-controlled imaging and structural processing via high-fidelity vector scans.