Lithography-Compatible Al ₂ O ₃ Stressor for Strain-Modulated T-to-H Phase Evolution of TaS ₂

Crystalline phases of transition-metal dichalcogenides offer unique structural configurations and tunable properties, driving phase engineering toward advanced fundamental and applied research. While strain is a recognized driver for modulating phase evolution, achieving spatially precise control over phase transitions remains a significant challenge. In this work, we present a lithography-compatible technique to modulate the phase evolution of TaS 2 flakes by using patterned Al 2 O 3 nanofilm stressors. By employing standard photolithography and lift-off processes, exfoliated 1T-TaS 2 flakes were integrated with controllable patterned Al 2 O 3 overlayers. Through a combination of on-chip comparative Raman spectroscopy and cross-sectional scanning transmission electron microscopy, we demonstrate that the strain induced by the Al 2 O 3 stressor is the governing factor in modulating TaS 2 phase evolution with a thickness-dependent mechanical response. Our work provides a facile and scalable platform for spatially precise strain engineering to modulate phase transitions in transition-metal dichalcogenides toward the fabrication of phase-engineered structures in future nanoelectronic studies.