The Effect of Sputtering Sequence Engineering in Superlattice-like Sb-Rich-Based Phase Change Materials

Area of Science:

• Materials Science
• Thin Film Technology
• Nanotechnology

Background:

• Phase change materials (PCMs) are crucial for data storage applications.
• Superlattice-like (SLL) structures offer potential for enhanced material properties.
• Optimizing thermal stability is key for reliable data retention in PCMs.

Purpose of the Study:

• To investigate the thermal stability of SLL thin films with varying sputtering sequences.
• To compare the data retention capabilities of SLL [Ge8Sb92/GeTe] and SLL [GeTe/Ge8Sb92] configurations.
• To elucidate the relationship between sputtering sequence, atomic diffusion, and thermal performance.

Main Methods:

• Fabrication of SLL thin films using sputtering techniques.
• Systematic variation of sputtering sequences: SLL [Ge8Sb92(25nm)/GeTe(25nm)] and SLL [GeTe(25nm)/Ge8Sb92(25nm)].
• Measurement of ten-year data retention (T) at elevated temperatures (124.3 °C and 151.9 °C).

Main Results:

• Both SLL configurations exhibited significantly enhanced ten-year data retention compared to Ge2Sb2Te5 (85 °C).
• SLL [GeTe(25nm)/Ge8Sb92(25nm)] demonstrated superior thermal stability (151.9 °C) over SLL [Ge8Sb92(25nm)/GeTe(25nm)] (124.3 °C).
• Superior stability in SLL [GeTe/Ge8Sb92] is attributed to Sb diffusion, reducing the impact of Sb precipitates.

Conclusions:

• The sputtering sequence critically influences the thermal stability and atomic behavior of SLL phase change materials.
• The SLL [GeTe/Ge8Sb92] configuration offers a promising pathway for developing advanced phase change materials with enhanced thermal performance.
• Understanding atomic diffusion mechanisms is vital for designing next-generation data storage materials.