Synthesis of Large-Area Crystalline MoS2 by Sputter Deposition and Pulsed Laser Annealing

Abstract

The wafer-scale synthesis of layered transitional metal dichalcogenides presenting good crystal quality and homogeneous coverage is a challenge for the development of next-generation electronic devices. This work explores a fairly unconventional growth method based on a two-step process consisting in sputter deposition of stochiometric MoS2 on Si/SiO2 substrates followed by nanosecond UV (248 nm) pulsed laser annealing. Large-scale 2H-MoS2 multi-layer films were successfully synthetized in a N2-rich atmosphere thanks to a fine-tuning of the laser annealing parameters by varying the number of laser pulses and their energy density. The identification of the optimal process led to the success in achieving a (002)-oriented nanocrystalline MoS2 film without performing post-sulfurization. It is noteworthy that the spatial and temporal confinement of laser annealing keeps the Si/SiO2 substrate temperature well below the back-end-of-line temperature limit of Si CMOS technology (770 K). The synthesis method described here can speed up the integration of large-area 2D materials with Si-based devices, paving the way for many important applications.