Atom probe tomography using an extreme ultraviolet trigger pulse

Area of Science:

• Materials Science
• Physics
• Analytical Chemistry

Background:

• Atom probe tomography (APT) is a key technique for nanoscale materials analysis.
• Conventional APT systems use visible or near-UV lasers for field ion evaporation.
• Limitations exist in current laser-based triggering methods for certain materials.

Purpose of the Study:

• To introduce and characterize an APT instrument utilizing ultrafast extreme ultraviolet (EUV) pulses.
• To demonstrate the efficacy of EUV light in triggering field ion emission for materials analysis.
• To detail the design and performance of the EUV beamline for APT applications.

Main Methods:

• Generation of tunable EUV light (25-45 eV) using high harmonic generation in a noble-gas-filled capillary.
• Delivery of EUV pulses to the APT specimen via a custom vacuum beamline.
• Characterization of EUV spectrum, focus spot size, and long-term source stability.
• Demonstration of APT analysis on semiconductors (Si, GaN) and insulators (Al2O3).

Main Results:

• Successful generation and delivery of tunable EUV pulses to the APT specimen.
• Characterization of the EUV beamline performance, including spectral evolution and focus spot size.
• Demonstrated long-term stability of the EUV source (>1 year).
• Successful field ion emission and APT analysis of Si, GaN, and Al2O3 using EUV pulses.

Conclusions:

• Ultrafast EUV pulses are a viable and effective alternative for triggering field ion emission in APT.
• This new method expands the applicability of APT to a wider range of materials, including insulators.
• The developed EUV-based APT system offers a stable and high-performance solution for atomic-resolution 3D materials characterization.