Scratching lithography for wafer-scale MoS₂ monolayers

Abstract

Monolayer MoS2 is an emerging two-dimensional (2D) semiconductor with promise on novel electronics and optoelectronics. Standard micro-fabrication techniques such as lithography and etching are usually involved to pattern such materials for devices but usually face great challenges on yielding clean structures without edge, surface and interface contaminations induced during the fabrication process. Here a direct writing patterning approach for wafer-scale MoS2 monolayers is reported. By controllable scratching by a tip, wafer-scale monolayer MoS2 films on various substrates are patterned in an ultra-clean manner. MoS2 field effect transistors fabricated from this scratching lithography show excellent performances, evidenced from a room-temperature on–off ratio exceeding 1010 and a high field-effect mobility of 50.7 cm2 V−1 s−1, due to the cleanness of as-fabricated devices. Such scratching approach can be also applied to other 2D materials, thus providing an alternate patterning strategy to 2D-materials based devices.

Fabrication Technologies for the On‐Chip Integration of 2D Materials

“…Reproduced with permission. [ 422 ] Copyright 2020, IOP Publishing. d) Moiré nanosphere lithography: (i) schematic illustration of patterning process.…”

“…(iv) Fluorescence microscopy images of MoS 2 films with different patterns. Reproduced with permission [422]. Copyright 2020, IOP Publishing.…”

Fabrication Techniques for the Integration of 2D Materials

“…8(c-iii)) has been achieved, [408] where transistors formed by patterned BP flakes exhibited enhanced current on-off ratios compared to pristine devices. Recently, a direct tip scratching approach [409] was utilized to achieve wafer scale patterning on graphene, MoS2, and h-BN. Fig.…”

“…Reproduced with permission. [409] Copyright 2020, IOP Publishing. (d) Moiré nanosphere lithography: (i) schematic illustration of patterning process.…”

“…(iv) fluorescence microscopy images of MoS2 films with different patterns. Reproduced with permission [409]. Copyright 2020, IOP Publishing.…”