---
title: "FIB Lamella: From Bulk to TEM Grid Interactive Lab | Sandbox Physics"
description: "How do you lift out a thin specimen without losing its support or useful material?"
canonical_url: "https://sandboxphysics.com/labs/fib-milling/"
language: "en"
page_type: "lab"
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  zh-CN: "https://sandboxphysics.com/zh/labs/fib-milling/"
last_modified: "2026-10-27"
---

E19 · Lift-out and thinning

# FIB Lamella: From Bulk to TEM Grid

**How do you lift out a thin specimen without losing its support or useful material?** Attach the needle before cutting the last bridge, and attach the lamella to its grid before removing the needle. Leave enough material for a low-energy finishing pass: two specimens of equal thickness can retain different amounts of unaffected interior.

Prepare two trenches, attach a needle before cutting the last bridge, and drag the supported lamella toward a TEM grid. Fix it to the grid before separating the needle. Then thin both faces and compare a gentle finishing pass with a damaging one.

> Interactive simulation: open this page in a web browser to change the parameters and run the model.

Model assumptions

The face-milling history also tracks separate Ga and Xe implantation profiles in an assigned silicon-equivalent host. Exponential stopping ranges and retained fractions are teaching parameters; sputtering removes previously implanted atoms and each pass adds new ions. The profile starts at the first face pass and excludes implantation from trenching or the support steps. Its composition is a calculated expectation, separate from the affected-layer proxy, not a measured concentration. This teaching workflow follows a supported lamella from trench preparation through undercutting, needle attachment, release, transfer, grid attachment, needle separation and two-face thinning. Each operation keeps its settings. The lamella starts 600 nm thick and 1500 nm long; its height comes from the committed trench depth. Both faces lose the chosen thickness in a pass. The removed volume and an assigned silicon-like atomic density determine the modeled ion number and milling time. Ga/Xe sputter yields, the trench stripes, redeposition and the affected surface layer are assigned teaching laws. The surface layer is a damage proxy, not a measured amorphous thickness or implanted-ion profile. Contact tolerances, ideal welds and a fixed raised transfer path replace forces and collision dynamics. Undercutting and weld deposition are state changes, not dose-calibrated processes; reported ion totals cover trench and face milling only. There is no calibrated material transport, evolving shadowing, thermal damage, fracture mechanics, real SEM acquisition or instrument recipe. The inspection rays are illustrative. Height, lateral distance, thickness in the data card and hardware use separate schematic scales.

Physics tutorial

## Keep a Support Until the Next One Holds

**Background** An ion beam can expose a thin slice inside a bulk specimen. The slice still needs a way out: a needle takes its weight before the last bridge is cut, then a grid takes over before the needle is removed. Final thinning happens on that grid.

**Why it matters** Cutting a thin specimen free is only half the task. You must preserve its support and enough interior material to examine after the surfaces have been affected by the ion beam.

Start with the essentials

- **Focus question**: How do you lift out a thin specimen without losing its support or useful material?
- **One-sentence intuition**: Keep one support in place until the next connection is made.

### Core mathematical model

#### Remove equal thicknesses from two faces

$$
t_{j+1}=\max(0,t_j-2d_j)
$$

The setting is removal from each face. If the two cuts meet, the lamella is lost. The initial modeled thickness is 600 nm.

#### Count the removed volume

$$
\begin{aligned}V_j&=L H(t_j-t_{j+1})\\N_j&=nV_j/Y_j\\T_j&=eN_j/I_j\end{aligned}
$$

Length and height stay fixed during face milling. The density and yield are assigned. This counts the ion charge for normal-incidence face passes; the trench-angle setting does not change that separate geometry.

#### Interior left between affected surfaces

$$
t_{\rm core}=\max(0,t-2\delta)
$$

The two surface layers use one assigned depth. Removing a face can clear old damage and create a new layer. The model does not infer a measured implantation profile.

### Common difficulties

#### Teaching parameters

**Typical misconception** The displayed settings are a preparation recipe for my material.

**Better mental model** The face-milling history also tracks separate Ga and Xe implantation profiles in an assigned silicon-equivalent host. Exponential stopping ranges and retained fractions are teaching parameters; sputtering removes previously implanted atoms and each pass adds new ions. The profile starts at the first face pass and excludes implantation from trenching or the support steps. Its composition is a calculated expectation, separate from the affected-layer proxy, not a measured concentration. This teaching workflow follows a supported lamella from trench preparation through undercutting, needle attachment, release, transfer, grid attachment, needle separation and two-face thinning. Each operation keeps its settings. The lamella starts 600 nm thick and 1500 nm long; its height comes from the committed trench depth. Both faces lose the chosen thickness in a pass. The removed volume and an assigned silicon-like atomic density determine the modeled ion number and milling time. Ga/Xe sputter yields, the trench stripes, redeposition and the affected surface layer are assigned teaching laws. The surface layer is a damage proxy, not a measured amorphous thickness or implanted-ion profile. Contact tolerances, ideal welds and a fixed raised transfer path replace forces and collision dynamics. Undercutting and weld deposition are state changes, not dose-calibrated processes; reported ion totals cover trench and face milling only. There is no calibrated material transport, evolving shadowing, thermal damage, fracture mechanics, real SEM acquisition or instrument recipe. The inspection rays are illustrative. Height, lateral distance, thickness in the data card and hardware use separate schematic scales.

### Run the experiment

1. 01

   #### Compare damage and implanted ions

   After mounting and thinning, inspect the implantation profile. Change the ion source in advanced controls and commit a small final pass. Compare retained Ga and Xe with the affected-layer readout.

   **What to observe:** A new source adds its own species while removing some atoms from the earlier pass. A smaller affected layer does not by itself specify the remaining composition.

2. 02

   #### See why a thin slice is not enough

   Compare Thin and mounted with Thin but surface-damaged. Check the affected layer and the unaffected core.

   **What to observe:** Equal total thickness can leave quite different amounts of useful interior.

3. 03

   #### Prepare a new specimen

   Choose New specimen. Set the trench dose and protection in Advanced settings, mill the trenches, then undercut while retaining one bridge.

   **What to observe:** A shallow cut cannot release this lamella. The retained bridge still carries it.

4. 04

   #### Let the needle take over

   Drag the gold needle handle to the attachment point and attach it. Cut the last bridge, then lift clear.

   **What to observe:** The model refuses release before attachment and motion before release.

5. 05

   #### Transfer the support to the grid

   Drag the supported lamella to the grid stop, lower it and weld it to the post. Separate the needle only after this connection is made.

   **What to observe:** Touching the grid is different from being attached to it.

6. 06

   #### Choose the last face passes

   Thin both faces, leaving material for a low-energy finish. Check the 60–150 nm thickness target and the 5 nm surface-layer target.

   **What to observe:** A later slider change cannot alter an earlier pass. Milling through either face is irreversible for that specimen.

Physical conclusion

The order of preparation matters, and the last low-energy pass changes both thickness and surface condition.

Fields & matter · Starter path

## From a field to an electron microscope

Map an electric field and steer a charged particle. Then find the electron's wavelength and use electron beams to see a crystal and a surface.

[Start here → **Make an Electric Field Visible** Move the probe around a dipole and check that the field always points downhill on the potential landscape. Observe · 8 min](https://sandboxphysics.com/labs/electric-field/)

1. [1 Make an Electric Field Visible](https://sandboxphysics.com/labs/electric-field/)
2. [2 A Charge Bending through Fields](https://sandboxphysics.com/labs/charged-particle/)
3. [3 Electron Wavelength & Voltage](https://sandboxphysics.com/labs/electron-wavelength/)
4. [4 Electron Diffraction & Reciprocal Space](https://sandboxphysics.com/labs/electron-diffraction/)
5. [5 TEM Bright Field, Dark Field & SAED](https://sandboxphysics.com/labs/tem-mode-selector/)
6. [6 SEM Secondary-Electron Topography](https://sandboxphysics.com/labs/sem-topography/)

[View the full path →](https://sandboxphysics.com/topics/fields-and-matter/#starter-path)