Enhancement of Thermal Boundary Conductance between MoS2 and Dielectric Layer by Self-Assembled Monolayers

The 2D semiconductor monolayer MoS2 is expected to be a potential channel material to achieve higher miniaturization and integration in post-Moore era due to its exceptional electrical and optical properties. However, the weak van der Waals interaction between MoS2 and the dielectric substrate induces high interfacial thermal resistance and impedes the heat dissipation, leading to significant temperature rise and consequential device performance degradation. Here, self-assembled monolayers (SAM) are employed to modify the surface of dielectric SiO2 and enhance thermal boundary conductance (TBC) between MoS2 and dielectric layer. The surface roughness of dielectric SiO2 is improved by the SAM, depressing the photon scattering. More importantly, the interfacial bonding force is strengthened by the formation of chemical covalent N-Mo bonds between NH2-terminated SAM and MoS2, thus leading to a 118% TBC improvement between MoS2 and NH2-terminated SiO2 compared to pristine SiO2 substrate. Simultaneously, the current reduction caused by self-heating effect in the monolayer MoS2 field-effect transistor is eliminated and the maximum power density of the device is largely improved. The incorporation of SAM in 2D semiconductor nanoelectronics presents great potential for device thermal management and reliability improvement.