Thermal properties of In–Sb–Te films and interfaces for phase change memory devices

• MOCVD-deposited In–Sb–Te films, 34–110 nm thick, with 12 and 17 at.% Te.
• In–Sb–Te films capped between silicon oxide, silicon nitride and alumina.
• The intrinsic thermal conductivity does not change with capping layer.
• The thermal boundary resistance improves with alumina and silicon oxide.
• The thermal boundary resistance is related to the measured interfacial roughness.

The thermal properties of two different compositions (Te 12 and 17 at.%) of In–Sb–Te, obtained by metalorganic chemical vapour deposition, were investigated by the 3 ω method. The thermal conductivity of these chalcogenides, of interest for phase change memory applications, was found to decrease with increasing tellurium content. Thermal treatment at 480 °C of these materials caused an increase of their crystallinity and improved the thermal conductivity. However, this effect was more marked in the Te-poor composition than in the Te-rich one. In addition, the thermal boundary resistance between In–Sb–Te and various capping dielectrics (SiO2, Si3N4 and Al2O3) was measured and it was found to be closely correlated to the interlayer roughness, as indicated by X-ray reflectivity. In this regard, silicon oxide and alumina yielded a smoother and less resistive interface with In–Sb–Te than silicon nitride.

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