SEM Simulator

An educational simulator of a field-emission scanning electron microscope (SEM), running in the browser.

Open it: virtual-sem.bracara-photonics.com

What it does

• A realistic control panel with Beam Control, Navigation, Detectors and Alignments pages, 2D stigmator and beam-shift controls, and the column alignment procedures (final lens, stigmator centring, source tilt and shift).
• A 3D view of the vacuum chamber, stage and column next to the live SEM image.
• Images computed live from procedural, to-scale specimens: a MEMS device, a CPU die, an insect eye, SiO₂ dielectric, two-photon micro-optics, a silicon photonic IC, a DOE and a metalens, and patterned photoresist over alignment marks.
• A physically motivated model of focus and depth of field, astigmatism, probe size and current, accelerating voltage and interaction volume, sub-surface contrast, shot noise versus dwell time, charging and drift, low vacuum and beam deceleration.
• A step-by-step standard operating procedure and an interactive tutorial, from sample exchange and pump-down to a focused, stigmated and saved micrograph.

Notes

It is a training and demonstration tool: the physics is empirical and not calibrated to a specific instrument. Nothing leaves the browser; captures are saved locally.

Built with vanilla JavaScript and three.js. Vibe coded and validated by Diogo Aguiam and Joana Santos at INL.