Electronic Devices and Circuits Based on Wafer‐Scale Polycrystalline Monolayer MoS₂ by Chemical Vapor Deposition

Abstract

IntroductionRecently, 2D layered materials (2DLMs) have emerged as promising candidates for next generation nanoelectronic applications owing to their unique electronic properties and ultrathin 2D layered materials such as graphene and transition-metal dichalcogenides (TMDCs) have emerged as promising candidates for next-generation nanoelectronic applications due to their atomically thin thicknesses and unique electronic properties. Among TMDCs, molybdenum disulfide (MoS 2 ) has been extensively investigated as a channel material for field-effect transistor (FET) and circuit realization. However, to date most reported works have been limited to exfoliated MoS 2 nanosheets primarily due to the difficulty in synthesizing large-area and high-quality MoS 2 thin film. A demonstration of wafer-scale monolayer MoS 2 synthesis is reported by chemical vapor deposition (CVD), enabling transistors, memristive memories, and integrated circuits to be realized simultaneously. Specifically, building on top-gated FETs with a high-κ gate dielectric (HfO 2 ), Boolean logic circuits including inverters and NAND gates are successfully demonstrated using direct-coupled FET logic technology, with typical inverters exhibiting a high voltage gain of 16, a large total noise margin of 0.72 V DD at V DD = 3 V, and perfect logic-level matching. Additionally, resistive switching is demonstrated in a MoS 2 -based memristor, indicating that they have great potential for the development of resistive random-access memory. By virtue of scalable CVD growth capability, the way toward practical and large-scale electronic applications of MoS 2 is indicated. 2D Electronics

Synthesis of two‐dimensional transition metal dichalcogenides for electronics and optoelectronics

“…The creation of those basic logic gates enables the organization of virtually any digital integrated circuits and opens up a scalable pathway to high‐performance logic applications using solution‐processable 2D semiconductor inks. Wang et al 182 demonstrated a practical approach to realizing fundamental building blocks for digital electronics based on large‐scale monolayer MoS 2 film synthesized via a CVD process. Ni foam was used as an acting barrier to limit the deposition rate of the precursor and improve the film uniformity.…”

“…E, The detailed arrangement of substrate, precursor flow, and Ni foam. D,E, Reproduced with permission from Reference 182. F, Schematic of circuit fabrication on a MoTe 2 layer by conventional lithography and laser writing.…”

Recent progress on kinetic control of chemical vapor deposition growth of high-quality wafer-scale transition metal dichalcogenides

“…Nickel oxide (NiO) foam was rst used as a barrier to control the deposition rate of Mo precursors on the substrate for the uniform growth of MoS 2 lms, but the evaporation rate was fast which led to uncontrollable reaction kinetics. 15,39 Moreover, the accelerated Mo release driven by the initial S evaporation, which prohibits the effective kinetics modulation, is yet to be addressed. To solve these problems, Shi et al 34 provided an oxide-inhibitor-assisted growth strategy to produce high-quality 2D Mo(S, Se, Te) 2 monolayer lms (Fig.…”

“…Besides, these solid transition metal salts can dissolve in water and then can be conveniently spin-coated on a substrate with uniform distribution. An annealing process at high temperature is needed to form the molten liquid precursor during the reaction, [38][39][40] which can be treated as a special liquid precursor. For example, Liu et al 41 introduced a molten-liquid intermediated CVD process for the growth of large-area TMDs with uniform thickness and a continuous monolayer (Fig.…”

An in-memory computing architecture based on two-dimensional semiconductors for multiply-accumulate operations

“…Compared to silicon and other TMDs with a narrower bandgap, monolayer MoS 2 has a relatively wide bandgap (~1.8 eV) to enable a large current on/off ratio in its fieldeffect transistors (FETs) 32 . Now wafer-scale continuous MoS 2 films can already be synthesized by chemical vapor deposition (CVD) methods 33 and transferred to arbitrary substrates 34 . The device processing techniques have also been intensively investigated to address early criticism of 2D-FETs, such as the realization of Ohmic contact and integration of high-k dielectrics [35][36][37] .…”