Phonon-limited mobility and quantum transport in fluorinated diamane MOSFETs from the first-principles calculations

Two-dimensional diamane with outstanding properties is promising for advanced nanodevice applications, whereas a comprehensive understanding of phonon-limited mobility as well as the prediction of device perfor-mance limit is still lacking. Here we report on phonon-limited mobility simulation in fluorinated diamane monolayer using first-principles calculations, with consideration of both elastic and inelastic phonon scattering processes based on Boltzmann transport equation. We construct sub-7 nm fluorinated diamane metal-oxide-semiconductor field-effect transistors (MOSFET) to investigate their quantum transport properties by first-principles calculations based on density functional theory coupling with the non-equilibrium Green's function formalism. Our findings show that fluorinated diamane mobility is concentration-dependent, with the electron and hole mobility reaching as high as 4390 and 10100 cm2V- 1s- 1, respectively, at the 1014 cm-2 carrier con-centration. Our simulations reveal that the key figures of merits (FOMs) of fluorinated diamane MOSFETs are benchmarked against the International Technology Roadmap for Semiconductors (ITRS) standards for high-performance (HP) and low-power (LP) applications, showing superior potential compared to the most re-ported 2D materials. The simulated results demonstrate that the on-current, delay time, and power-delay product meet the ITRS requirements for HP and LP applications, including devices constructed with nano-scale channel length (>= 3 and 5 nm) respectively. Finally, we show that the performance of a 32-bit ALU based on fluorinated diamane MOSFETs is comparable with emerging beyond-CMOS devices. Thus, our results shed light on the electronic properties of fluorinated diamane, making it superior to serve as a channel material in the post-silicon era.

Automated summary

This study investigates the phonon-limited mobility and device performance limits in fluorinated diamane monolayers. The simulations show that the mobility of fluorinated diamane is concentration-dependent, with high electron and hole mobility at certain carrier concentrations. The findings also demonstrate that fluorinated diamane MOSFETs have superior potential compared to other 2D materials and can meet the requirements for high-performance and low-power applications.