Synthesis of Two-Dimensional (2D) Materials, Tunable Hybrid Dielectric Deposition, and its Application in 2D Nanoelectronics

The semiconductor industry, which has developed and progressed based on Moore’s Law, has been approaching physical and quantum mechanical limitations in continuously scaling down the size of key building blocks in integrated circuits. In this regard, two-dimensional (2D) materials has been considered as an alternative channel materials instead of Si, since they offer the possibility of downscaling channel thicknesses to the atomic level while retaining improved electrostatic control of the devices and allowing the suppression of short channel effects. Although 2D materials, such as graphene, hexagonal boron nitride (h-BN), and transition metal dichalcogenides (TMDs), have proposed many unique properties for many advanced electronic applications for the last decade, bottom-up production methods of 2D materials with properties appropriate for specific applications must be formulated without a post-deposition transfer process. This dissertation focuses on the development of 2D materials (graphene and h-BN) deposition as well as uniform dielectrics on TMDs, using various techniques, including ALD, MLD, and CVD. First, the effect of Ni catalyst for graphitic carbon formation is studied using CVD at a high temperature of 800 °C. Then, the growth of graphene/graphite thin films directly on SiO2 is explored using diffusion-based graphitization mechanism of amorphous carbon (a-C) through Ni catalyst. Second, atomic layer deposition (ALD) of BCl3 and NH3 precursors at 600 °C is studied to deposit high-quality and scalable h-BN thin films directly on both SiO2 and 2D materials (HOPG and MoS2). Lastly, molecular atomic layer deposition (MLD) of octenyltrichlorosilane (7-OTS) with inorganic linkers, such as Al2O3 or TiO2, is explored at a low temperature of 100 °C in order to integrate ultrathin organic-inorganic hybrid dielectrics with tunable characteristics on 2D MoS2