Rubbing-Induced Site-Selective Growth of MoS2 Device Patterns.

The superior electronic and mechanical properties of two-dimensional layered transition-metal dichalcogenides could be exploited to make a broad range of devices with attractive functionalities. However, the nanofabrication of such layered material-based devices still needs resist-based lithography and plasma etching processes for patterning layered materials into functional device features. Such patterning processes lead to unavoidable contaminations, to which the transport characteristics of atomically thin-layered materials are very sensitive. More seriously, such lithography-introduced contaminants cannot be safely eliminated by conventional semiconductor cleaning approaches. This challenge seriously retards the manufacturing of large arrays of layered material-based devices with consistent characteristics. Toward addressing this challenge, we introduce a rubbing-induced site-selective growth method capable of directly generating few-layer MoS2 device patterns without the need of any additional patterning processes. This method consists of two critical steps: (i) a damage-free mechanical rubbing process for generating microscale triboelectric charge patterns on a dielectric surface and (ii) site-selective deposition of MoS2 within rubbing-induced charge patterns. Our microscopy characterizations in combination with finite element analysis indicate that the field magnitude distribution within triboelectric charge patterns determines the morphologies of grown MoS2 patterns. In addition, the MoS2 line patterns produced by the presented method have been implemented for making arrays of working transistors and memristors. These devices exhibit a high yield and good uniformity in their electronic properties over large areas. The presented method could be further developed into a cost-efficient nanomanufacturing approach for producing functional device patterns based on various layered materials.