Deterministic grayscale nanotopography to engineer mobilities in strained MoS2 FETs
Xia Liu, Berke Erbas, Ana Conde‐Rubio, Norma Rivano, Z. Wang, Jin Jiang, Siiri Bienz, Naresh Kumar, Thibault Sohier, Marcos Penedo, Mitali Banerjee, Georg E. Fantner, Renato Zenobi, Nicola Marzari, András Kis, Giovanni Boero, Juergen Brügger
Abstract
Abstract Field-effect transistors (FETs) based on two-dimensional materials (2DMs) with atomically thin channels have emerged as a promising platform for beyond-silicon electronics. However, low carrier mobility in 2DM transistors driven by phonon scattering remains a critical challenge. To address this issue, we propose the controlled introduction of localized tensile strain as an effective means to inhibit electron-phonon scattering in 2DM. Strain is achieved by conformally adhering the 2DM via van der Waals forces to a dielectric layer previously nanoengineered with a gray-tone topography. Our results show that monolayer MoS 2 FETs under tensile strain achieve an 8-fold increase in on-state current, reaching mobilities of 185 cm²/Vs at room temperature, in good agreement with theoretical calculations. The present work on nanotopographic grayscale surface engineering and the use of high-quality dielectric materials has the potential to find application in the nanofabrication of photonic and nanoelectronic devices.