FIB-TEM sample preparation technique

The microstructure of materials plays a decisive role in the mechanical, optical, electrical and other physicochemical properties of materials. Transmission electron microscopy, as an important means of material characterisation, can not only study the structure of crystals in diffraction mode, but also obtain a high-resolution image of real space in imaging mode, i.e., imaging the atoms in the material and directly observing the microstructure of the material.

Here we demonstrate the method of preparing transmission electron microscopy samples by FIB specifically.

First, we place the in-situ chip at 45 degrees on the sample stage, and then place the test sample on the chip;

Processing of the sample by simultaneous operation of electron count and ion count.

The first step of sample processing is to accumulate platinum in the target deposition area with a platinum strip of approximately 1 µm in width.

In the second step, groove preparation, which is often referred to as bombardment preparation, is performed on the front and back sides of the platinum strip, and the sample is bombarded to a depth of about 3 microns.

The sample stage is then orientated and rotated to the left side of the sample to separate the sample from the bottom thin zone.

The micromanipulator is fixed to the thin section by platinum deposition, the sample is then rotated to the right side and the bombardment is continued until the sample is completely separated.

In the fourth step, the separated sample is fixed parallel to the sample stage, the thin slice is fixed to the chip, and the display operator is released to rotate the chip.

In the last step, further thinning is performed in the direction of the thickness of the already prepared thin zone, so as to meet the requirements of transmission electron microscopy on the thickness of the sample.

Note that during the thinning process, the sample must be tilted and rotated to match the angle of the thin film.