Strain Engineering for Enhancing Carrier Mobility in MoTe(2) Field‐Effect Transistors

Molybdenum ditelluride (MoTe(2)) exhibits immense potential in post‐silicon electronics due to its bandgap comparable to silicon. Unlike other 2D materials, MoTe(2) allows easy phase modulation and efficient carrier type control in electrical transport. However, its unstable nature and low‐carrier mobility limit practical implementation in devices. Here, a deterministic method is proposed to improve the performance of MoTe(2) devices by inducing local tensile strain through substrate engineering and encapsulation processes. The approach involves creating hole arrays in the substrate and using atomic layer deposition grown Al(2)O(3) as an additional back‐gate dielectric layer on SiO(2). The MoTe(2) channel is passivated with a thick layer of Al(2)O(3) post‐fabrication. This structure significantly improves hole and electron mobilities in MoTe(2) field‐effect transistors (FETs), approaching theoretical limits. Hole mobility up to 130 cm(−2) V(−1) s(−1) and electron mobility up to 160 cm(−2) V(−1) s(−1) are achieved. Introducing local tensile strain through the hole array enhances electron mobility by up to 6 times compared to the unstrained devices. Remarkably, the devices exhibit metal–insulator transition in MoTe(2) FETs, with a well‐defined critical point. This study presents a novel technique to enhance carrier mobility in MoTe(2) FETs, offering promising prospects for improving 2D material performance in electronic applications.