Small-Angle X-ray Scattering (SAXS)

Figure 1. FIB equipment.

Features

The FIB can have a diameter from a few nm to several hundred nm. By scanning the beam on the sample surface, it is possible to shave (sputter) a specific region or to form a film of carbon (C), tungsten (W), platinum (Pt) in a specific region on the sample surface.

• Arbitrary shape processing by high-resolution dry etching (several nm to several tens of \(\mu\text{m}\))

• Preparation of thin samples for observation by SEM, scanning transmission electron microscopy (STEM), TEM, and SEM-STEM (location of cross-sections can be specified)

• Thin film deposition and \(\mu\text{m}\)-resolution patterning

• High-resolution SIM (4 nm) thanks to high acceleration voltage (30 kV)

• SIM analysis of crystalline metal grains possible, for example, Al, Cu

Application Examples

• Preparation of SEM, SEM-STEM, and TEM samples

• Disconnecting, joining, and short-circuiting device wires

• Observation and measurement of cross sections using SEM and SIM slice-and-view

• Determining the precise location of sample features

• Lateral surface analysis using SIM

Principle

Sample processing by fine ion beam

When Ga ions (Xe or Ar in some cases) are irradiating the sample, atoms and molecules on the sample are expelled and escape into vacuum together with the ions. This type of sputtering ensures fabrication of holes and smooth cross-sections with submicron accuracy (see Figure 2).

3D structure formation by FIB-assisted MOCVD

When a source gas, such as tungsten hexacarbonyl, is sprayed onto the sample surface and adsorbed, the FIB can selectively induce chemical change of the adsorbed source gas. This enables deposition of patterned thin metal films in the irradiated areas (see Figure 3) by means of metal-organic chemical vapour deposition (MOCVD).

Sample surface observation with a secondary electron detector

If the sub-\(\mu\)m scanning FIB is synchronized with a secondary electron detector, the sample surface can be imaged with sub-\(\mu\)m resolution. This is the principle of SIM.

Figure 2. Etching with the associated emission of secondary electrons.	Figure 3. Deposition of W film

Data examples

Drilling and thin-film formation

Figure 4. Sample SIM image.	Figure 5. Sub-\(\mu\)m holes fabricated by FIB sputtering.	Figure 6. Selective formation of a W film by FIB-assisted MOCVD.

TEM sample preparation

To prepare the sample, the areas surrounding the region of interest (ROI) are first removed by drilling vertical holes (Figure 7). Next the micro sample is exposed by means of the probe (Figure 8) which attaches to the sample by deposition of FIB-MOCVD (Figure 9). It is then moved by the probe from the mesh end (Figure 10) to the sample holder (Figure 11), which then is used for thinning specific parts of the sample by FIB. The complete sample for TEM analysis is shown in Figure 12.

Figure 7. Detachment of sample circumference.	Figure 8. Disconnecting the sample using the probe.	Figure 9. Exposing the sample.

Figure 10. Moving sample on the mesh end face.	Figure 11. Fixing and thinning the sample for TEM observation.	Figure 12. Complete TEM sample for cross-section analysis (view perpendicular to Figure 11).

Data delivery formats

SIM images: TIFF or JPEG files

Measurement specifications

Property	Value	Unit	Notes
Maximum wafer sample diameter	300	mm	Max thickness 5 mm. Depends on equipment.
Maximum sample height	20	mm	30 mm diameter sample. Depends on equipment.
Processing line width	5-40	\[\mu\text{m}\]	Usually about 20 \(\mu\text{m}\)
Resolution	4	nm	30 kV acceleration voltage
Acceleration voltage	1-40	kV
SIM image magnification	0.1-100	\[{\times 10}^{3}\]

Items for enquiries

• Purpose and scope of the analysis

• Sample information:

  1. Quantity, availability of pre-analysis samples

  2. Shape, layer structure, film thickness, surface characteristics, prior processing (if any), desirable observation locations, possible sample cleavage positions

  3. Care instructions

• Delivery date:

  1. Desired delivery dates of preliminary and final results

  2. Handling instructions

• Other relevant information

Caution

• Confirm sample dimensions with MST in advance