Scalable Two-Dimensional Lateral Metal/Semiconductor Junction Fabricated with Selective Synthetic Integration of...

The construction of manufacturable, stable, high-quality metal/semiconductor junction structures is of fundamental importance to implement higher-level devices and circuit systems. Owing to the unique features of two-dimensional (2D) materials, namely, that intralayer atoms are covalently bonded, whereas interlayer atoms are held together by weak attractive interactions, there are several studies on the fabrication and identification of the peculiar properties of various 2D heterostructures. However, large-scale 2D lateral metal/semiconductor junction structures with acceptable levels of manufacturability and quality have not yet been demonstrated, which is among the critical technological hurdles to overcome for the realization of 2D material-based electronic and photonic devices. This paper reports the fabrication of a manufacturable large-scale metal (Mo₂C)/semiconductor (MoS₂) junction via selective synthetic integration and a lithographically patterned SiO₂ masking layer. It is demonstrated that whereas chemical conversion to Mo₂C occurs in the exposed chemical vapor deposition-grown MoS₂ part, the MoS₂ layer under the SiO₂ masking layer is protected from chemical conversion, so that a scalable Mo₂C/MoS₂ heterostructure is integrated down to nanometer-scale dimensions. Excellent contact resistance of 2.1 kΩ·μm is achieved from this lateral junction structure, providing a manufacturable and highly stable metal/semiconductor building block for real implementation of 2D material-based nanoscale device integration.