3D SEM Charging Artifact Simulator

SEM Imaging (3D)

Beam energy 15 keV

Sample conductivity 0.15

Charging-artifact strength 1.0×

Image contrast

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Charge buildup

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Verdict

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How it works

This is the same physics as the 2D SEM simulator, rendered on an actual 3D sample surface so you can see why edges brighten: secondary-electron yield depends on the angle between the beam and the local surface normal, δ(θ) ≈ δ0/cos θ, so a steep facet genuinely emits more secondaries per unit area than a flat top. The beam sweeps the surface row by row exactly like a real SEM raster; each pass deposits charge on non-conductive vertices, and that charge modulates emitted brightness on later passes — visible here as streaks that grow and drift along the scan direction rather than sitting still on the geometry.

δ(θ) ≈ δ0 / cos θ                 (edge brightening — real, geometric)
Q(t+dt) = Q(t)(1−bleed·dt) + dose·(1−cond)·dt   (charging — artifact)
vertexColor ∝ δ(θ) + artifactStrength · Q

Beam energy — sets the charge dose per scan line; higher energy on an insulator produces stronger, faster-blooming streaks.
Sample conductivity — how fast deposited charge bleeds away; a coated/grounded sample relaxes almost immediately and the streaks vanish.
Beam sweep — pause it to freeze the raster and compare the streak pattern (artifact, aligned to scan rows) against the underlying bump geometry (real, aligned to the sample itself) by orbiting the camera.

Real-world relevance: rotating the sample (as you can here) is exactly how microscopists distinguish the two — genuine topographic brightening stays fixed to the specimen when you tilt it, while a charging streak stays fixed to the raster direction.

Edge brightening (real) Beam / current scan row Charging streak (artifact)

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