The Ta Seed-Buffer Layer Microstructure and Its Influence on the Magnetic and Structural Parameters of CoFeB/MgO...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Thin Film Technology

Background:

• Understanding the structural and magnetic properties of multilayer thin films is crucial for developing advanced electronic devices.
• The interface quality and magnetic dead layer significantly impact device performance.

Purpose of the Study:

• To investigate the effect of varying Ta buffer layer thickness on the structural and magnetic properties of Ta/CoFeB/MgO multilayers.
• To correlate structural characteristics with magnetic properties and interface quality.

Main Methods:

• Deposition of CoFeB wedge layers on Ta buffers with thicknesses of 5, 10, and 15 nm.
• Structural analysis using X-ray reflectivity and morphological roughness measurements.
• Magnetic property evaluation through temperature-dependent measurements and magnetic dead layer analysis.

Main Results:

• Ta buffer structure transitions from amorphous (5 nm) to β-tetragonal disordered (thicker Ta).
• Interface roughness decreases with increasing CoFeB layer thickness and is lowest for the amorphous 5 nm Ta buffer.
• A strong (001)-oriented MgO texture is observed, enhanced by smoother Ta buffers.
• Magnetic dead layer thickness increases as Ta buffer thickness decreases.

Conclusions:

• Ta buffer layer thickness critically affects the structural evolution and interface properties of Ta/CoFeB/MgO multilayers.
• Optimizing Ta buffer thickness is essential for minimizing interface roughness and magnetic dead layer formation.
• These findings provide insights for designing high-performance magnetic multilayer devices.