Elemental Distribution in Multilayer Systems by Laser-Assisted Atom Probe Tomography with Various Analysis Directions

Area of Science:

• Materials Science
• Surface Science
• Nanotechnology

Background:

• Magnetic multilayer systems are crucial for advanced electronic devices.
• Understanding elemental distribution at interfaces is key to optimizing device performance.
• Atom probe tomography (APT) is a powerful technique for nanoscale elemental analysis.

Purpose of the Study:

• To investigate the influence of APT analysis direction on elemental distribution in a Si/Ta/NiFe/Ru/CoFeB/Ru/NiFe multilayer.
• To characterize the behavior of Ruthenium (Ru) and Boron (B) atoms during APT analysis.
• To determine the necessity of multi-directional analysis for accurate interface characterization.

Main Methods:

• Utilized atom probe tomography (APT) to analyze a magnetic multilayer system.
• Performed APT analysis along different directions: parallel, anti-parallel, and perpendicular to the film growth direction.
• Examined the elemental distribution of key elements, particularly Ru and B.

Main Results:

• Elemental distributions of Ru and B were strongly dependent on the APT analysis direction.
• Boron distribution within the CoFeB layer varied significantly with analysis direction, appearing near different Ru interfaces or homogeneously.
• The observed B behavior influenced the distribution of the underlying Ru layer.

Conclusions:

• APT analysis direction critically affects the observed elemental distribution in multilayer systems with varying evaporation fields.
• Accurate evaluation of elemental distribution at interfaces in such systems requires multi-directional APT analysis.
• Findings highlight the importance of considering analysis artifacts in nanoscale material characterization.