Topological insulators (TIs), characterized by topologically protected surface states within the band structure, hold promise for spintronic devices owing to their efficient charge-to-spin current conversion. However, most TIs exhibit significant degradation when temperatures reach 350–400 °C in the annealing process of semiconductor fabrication, limiting their integration into TIs-based magnetic random-access memory (MRAM) technologies. Here, we report the magnetron sputtering growth of high-quality ${\mathrm{Sb}}_2{\mathrm{Te}}_3$ thin films on $\mathrm{Si}/{\mathrm{Si}\mathrm{O}}_2$ substrates, achieving smooth surfaces and notable thermal stability. These films retain structural integrity and functional performance after 1 h of annealing at 350 °C. When integrated into ${\mathrm{Sb}}_2{\mathrm{Te}}_3/\mathrm{Ti}/\mathrm{Co}\mathrm{Fe}\mathrm{B}/\mathrm{Mg}\mathrm{O}$ heterostructures, the 350 °C-annealed films exhibit a spin Hall angle of 1.6–3.5 (measured from 27 to 70 °C), surpassing conventional heavy metals ($\mathrm{Pt}$, $\mathrm{Ta}$) by an order of magnitude and significantly outperforming chemically vapor-deposited ${\mathrm{Sb}}_2{\mathrm{Te}}_3$ films. Furthermore, by engineering a wedge-shaped asymmetric ${\mathrm{Sb}}_2{\mathrm{Te}}_3/\mathrm{Ti}$(wedged)/$\mathrm{Co}\mathrm{Fe}\mathrm{B}/\mathrm{Mg}\mathrm{O}$ structure, we achieve fieldfree perpendicular magnetization switching with a critical current density on the order of ${10}^5\mathrm{A}/{\mathrm{cm}}^2$—comparable to devices fabricated via molecular beam epitaxy. These findings highlight the viability of sputtered ${\mathrm{Sb}}_2{\mathrm{Te}}_3$ for energy-efficient spintronics, offering industrial-compatible fabrication, robust high temperature resilience, and low-power operation—critical attributes for advancing next-generation MRAM technologies.

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• Magnetization switching
• Spin-orbit coupling
• Spintronics
• Surface states
• Devices for digital logic, storage & processing
• Magnetic multilayers
• Topological insulators
• Sputtering