MoS₂ Transistors Fabricated via Plasma-Assisted Nanoprinting of Few-Layer MoS₂ Flakes into Large-Area Arrays

Abstract

Large-area few-layer-MoS2 device arrays are desirable for scale-up applications in nanoelectronics. Here we present a novel approach for producing orderly arranged, pristine few-layer MoS2 flakes, which holds significant potential to be developed into a nanomanufacturing technology that can be scaled up. We pattern bulk MoS2 stamps using lithographic techniques and subsequently transfer-print prepatterned MoS2 features onto pristine and plasma-charged SiO2 substrates. Our work successfully demonstrates the transfer printing of MoS2 flakes into ordered arrays over cm(2)-scale areas. Especially, the MoS2 patterns printed on plasma-charged substrates feature a regular edge profile and a narrow distribution of MoS2 flake thicknesses (i.e., 3.0 ± 1.9 nm) over cm(2)-scale areas. Furthermore, we experimentally show that our plasma-assisted printing process can be generally used for producing other emerging atomically layered nanostructures (e.g., graphene nanoribbons). We also demonstrate working n-type transistors made from printed MoS2 flakes that exhibit excellent properties (e.g., ON/OFF current ratio 10(5)-10(7), field-effect mobility on SiO2 gate dielectrics 6 to 44 cm(2)/(V s)) as well as good uniformity of such transistor parameters over a large area. Finally, with additional plasma treatment processes, we also show the feasibility of creation of p-type transistors as well as pn junctions in MoS2 flakes. This work lays an important foundation for future scale-up nanoelectronic applications of few-layer-MoS2 micro- and nanostructures.

Seeded growth of highly crystalline molybdenum disulphide monolayers at controlled locations

“…However, this method typically leads to growth of MoS 2 flakes in uncontrolled locations on the substrate, which limits its utility for many applications. Control over the position of MoS 2 flakes on oxidized silicon has been reported through the use of stamping 18 and masking 19 techniques, but neither of these allowed for the creation of large (tens of micrometres) monolayer domains at predetermined locations with micrometre-scale resolution. Substrate patterning has been used to control nucleation and growth of crystalline flakes of two-dimensional topological insulator materials on mica 20 , but it remains unclear whether this approach can be generalized to MoS 2 on oxidized silicon.…”

Nanoimprint-Assisted Shear Exfoliation (NASE) for Producing Multilayer MoS2 Structures as Field-Effect Transistor Channel Arrays

“…Specifically, in this presented nanofabrication process, termed as nanoimprint-assisted shear exfoliation (NASE), multilayer MoS 2 structures prepatterned on a bulk MoS 2 stamp were imprinted into a polymeric fixing layer and subsequently exfoliated along a shear direction using a motor-driven roller tool. As compared to previously reported exfoliation methods for generating layered materials, 25,26 NASE can result in significantly improved transfer efficiency of prestructured MoS 2 features as well as uniformity of resultant flake thicknesses. Our transistor-based biosensors made from NASE-produced MoS 2 flakes exhibited a high device-to-device consistency in the sensor responses to specific biomarkers.…”

Scalable integration of periodically aligned 2D-MoS2 nanoribbon array

“…To date, several alternative nanofabrication techniques have been reported, which relies on the following four methods: (1) selective growth on the patterned templates, 12,13 (2) reactive ion etching using patterned masks, 14,15 (3) direct removal by scanning lasers or ions, 16,17 and (4) peeling, transfer, and filling methods by controlling a surface adhesion energy. [18][19][20] In method (1), the prepared Mo nanowires were converted to MoS 2 nanowires through pyrolysis in H 2 S ambient; however, these MoS 2 nanowires exhibited unstable electrical properties owing to a Y. Pak 20 reported the combined fabrication of polydimethylsiloxane (PDMS) micro-molding and thermolysis, achieving the MNR width of 157 nm.…”