Hydrogen Forward Scattering Spectrometry (HFS) is an ion scattering technique that is used to quantitatively determine the vertical distribution of hydrogen in thin films. During the process, He2+ ions hit the sample surface at a glancing angle, knocking hydrogen atoms out of the sample, which can then be analyzed using a solid state detector.
The ability to measure the composition and vertical distribution of hydrogen content within a thin film can be critical due to the potential impact of hydrogen on a film’s physical or electrical properties. Other techniques, such as Auger Electron Spectroscopy (AES), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Photoelectron Spectroscopy (XPS), cannot detect hydrogen; and while SIMS can measure hydrogen, quantification of the hydrogen by SIMS can be difficult and requires standards. This makes HFS a uniquely useful technique for thin film analysis.
Ideal Uses of HFS
- Depth profiling of Hydrogen in thin films
- Non-destructive H composition measurement
- Whole wafer analysis (up to 300 mm)
- Conductor and insulator analysis
- Large analysis area (1×7 mm)
- Useful information limited to thin films (<0.4 μm)
- Depth resolution of 300 Å
- Signal Detected: Forward scattered H atoms
- Elements Detected: 1H, 2H
- Detection Limits: 0.1-0.5 at%
- Depth Resolution: ~300 Å
- Imaging/Mapping: No
- Lateral Resolution/Probe Size: ≥1×7 mm