Study of Contact Properties for Semiconducting TMDCs Using Via Contacts Embedded in h-BN

The semiconducting transition metal dichalcogenides (TMDCs) are considered as a promising candidate for Si-based electronics. However, it is notorious particularly for a contact of semiconducting TMDCs especially when their thickness scales down to extreme thinness such as mono- to tri-layers. There have been some reports on contact issue and its remedy but most of them are discussed on multi-layered structures. According to our study, even though it showed a linear behavior at room temperature, a non-linear behavior could be observed at low temperature. Thus, it is very valuable to study contact properties to achieve ohmic contact even at low temperature. In this study, we evaluated the electrical properties of semiconducting TMDCs from mono- to tri-layers with different metals embedded in hexagonal boron nitride (h-BN) so as to uncover its contact properties. The fabricated devices show the higher performances in terms of current value and stability due to the lower contact resistance and ultraflat surface of h-BN so as to allow us to trace the intrinsic carrier transport and unique properties of the TMDCs.