High-mobility three-atom-thick semiconducting films with wafer-scale uniformity.

Title	High-mobility three-atom-thick semiconducting films with wafer-scale uniformity.
Authors	Kibum Kang, Saien Xie, Lujie Huang, Yimo Han, Pinshane Y. Huang, Kin Fai Mak, Cheol-Joo Kim, David Muller, Jiwoong Park
Magazine	Nature
Date	04/01/2015
DOI	10.1038/nature14417
Introduction	The foundation of contemporary electronics and optoelectronics relies heavily on the extensive production of semiconducting thin films. Reducing film thickness to the atomic, sub-nanometre scale presents significant advantages for ultrathin and flexible electronics, photovoltaics, and display technology, a feat challenging for conventional semiconductors such as silicon and gallium arsenide. Transition-metal dichalcogenides (TMDs) are excellent candidates, forming stable three-atom-thick monolayers with high electrical carrier mobility. Their direct growth on insulating substrates facilitates the batch manufacturing of high-performance, atomically thin transistors and photodetectors for industrial applications, eliminating the need for film transfer. Furthermore, TMDs possess distinctive electronic band structures that allow for advanced device capabilities, such as strong excitonic effects, bandgap tuning, indirect-to-direct bandgap transitions, piezoelectricity, and valleytronics. Despite these benefits, achieving large-scale growth of monolayer TMD films with consistent spatial uniformity and high electrical performance has persisted as a significant challenge. This study details the creation of high-mobility, 4-inch wafer-scale films of monolayer molybdenum disulphide (MoS2) and tungsten disulphide. These films were directly grown on insulating silicon dioxide substrates using an innovative metal-organic chemical vapour deposition technique, exhibiting outstanding spatial homogeneity across the entire wafer. The MoS2 films demonstrated impressive electrical performance, with electron mobilities of 30 cm² V⁻¹ s⁻¹ at room temperature and 114 cm² V⁻¹ s⁻¹ at 90 K, showing minimal dependence on position or channel length. Leveraging these films, we successfully achieved wafer-scale batch fabrication of high-performance monolayer MoS2 field-effect transistors, boasting a 99% device yield. Additionally, we demonstrated multi-level fabrication of vertically stacked transistor devices, paving the way for three-dimensional circuitry. This development represents a crucial advancement towards realising atomically thin integrated circuits.
Quote	Kibum Kang, Saien Xie and Lujie Huang et al. High-mobility three-atom-thick semiconducting films with wafer-scale homogeneity. 2015. DOI: 10.1038/nature14417
Element	Molybdenum (Mo) , Sulfur (S) , Tungsten (W) , Silicon (Si) , Oxygen (O) , Gallium (Ga) , Arsenic (As)
Topics	Deposition Processes
Industry	Electronics , Solar Energy , Research & Laboratory