# Real-Time External Control Combined with Image Post-Processing for Mitigating SEM Vibration Distortion

## TL;DR

This paper introduces a new method combining real-time control and image processing to reduce vibration distortion in scanning electron microscope (SEM) images.

## Contribution

The novel hybrid framework integrates real-time active suppression and post-processing to effectively mitigate multi-source vibration distortion in SEM imaging.

## Key findings

- The proposed framework reduces peak-to-peak value, edge transition width, and NIQE score by 39.4%, 91.7%, and 58.9%, respectively.
- Periodic vibration distortion is essentially eliminated at both 100 kx and 50 kx magnifications.
- The strategy is universally applicable without requiring vibration source localization.

## Abstract

Scanning electron microscopes (SEMs) are crucial for material characterization. They are highly susceptible to vibration from environmental sources, internal components, and other external factors, which can impair measurement accuracy. Traditional solutions are limited in addressing multi-source vibrations: passive isolation struggles with internal vibrations, while image post-processing cannot fundamentally correct large-amplitude deviations in the electron beam. Therefore, this study proposes a hybrid framework that combines real-time active hardware suppression with post-processing to mitigate vibration-induced distortion in SEM images. Using a self-developed external controller and software, the framework extracts periodic vibration features via FFT, quantifies scan line horizontal offset, and implements real-time inverse offset during imaging to suppress dominant-frequency vibration at the source. An adaptive median filtering algorithm is integrated with a Laplacian edge enhancement algorithm to address residual edge burrs, thereby balancing distortion suppression and detail preservation. Experiments at 100 kx magnifications demonstrate notable correction effects: the peak-to-peak value, edge transition width (ETW), and no-reference image quality (NIQE) score are reduced by 39.4%, 91.7%, and 58.9%, respectively. Consistent correction trends are observed at 50 kx, with periodic vibration distortion essentially eliminated across both magnifications. Furthermore, distortion can be regulated through the phase interaction between dwell time and vibration period, making the strategy universally applicable and easy to implement. Without the need for vibration source localization, the framework is compatible with various types of vibration interference. It provides a solution for mitigating vibration impacts in high-magnification, precise characterization of SEMs and offers a reference for anti-vibration optimization of other microscopic techniques, such as transmission electron microscopy (TEM) and atomic force microscopy (AFM).