A subthermionic tunnel field-effect transistor with an atomically thin channel

• Published in: Nature (London) 2015-10, Vol.526 (7571), p.91-95
• Main Authors: Sarkar, Deblina, Xie, Xuejun, Liu, Wei, Cao, Wei, Kang, Jiahao, Gong, Yongji, Kraemer, Stephan, Ajayan, Pulickel M., Banerjee, Kaustav
• Format: Article
• Language: English
• Subjects: 140/133; 140/146; 142/126; 147/143; 147/3; 639/301/1005/1007; 639/925/927/1007; Biosensors; Field-effect transistors; Germanium; Humanities and Social Sciences; Information technology; letter; Molybdenum; multidisciplinary; Science; Semiconductors; Silicon; Thermal properties; Transistors
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature15387

A new type of device, the band-to-band tunnel transistor, which has atomically thin molybdenum disulfide as the active channel, operates in a fundamentally different way from a conventional silicon (MOSFET) transistor; it has turn-on characteristics and low-power operation that are better than those of state-of-the-art MOSFETs or any tunnelling transistor reported so far. Novel transistor technology demonstrated Traditional transistor technology is fast approaching its fundamental limits, and two-dimensional semiconducting materials such as molybdenum disulfide (MoS 2 ) are seen as possible replacements for silicon in a next generation of high-density, lower-power chip electronics. A particularly promising prospect is their potential in band-to-band tunnel transistors, which operate in a fundamentally different way from conventional silicon (MOSFET) transistors. So far, few such devices with overall characteristics better than silicon transistors have been demonstrated. Now Kaustav Banerjee et al . have built a tunnel transistor by making a vertical structure with atomically thin MoS 2 as the active channel and germanium as the source electrode. It has turn-on characteristics and low-power operation that are better than those of existing silicon transistors, and the results will be of interest in a range of electronic applications including low-power integrated circuits, as well as ultra-sensitive bio sensors or gas sensors. The fast growth of information technology has been sustained by continuous scaling down of the silicon-based metal–oxide field-effect transistor. However, such technology faces two major challenges to further scaling. First, the device electrostatics (the ability of the transistor’s gate electrode to control its channel potential) are degraded when the channel length is decreased, using conventional bulk materials such as silicon as the channel. Recently, two-dimensional semiconducting materials 1 , 2 , 3 , 4 , 5 , 6 , 7 have emerged as promising candidates to replace silicon, as they can maintain excellent device electrostatics even at much reduced channel lengths. The second, more severe, challenge is that the supply voltage can no longer be scaled down by the same factor as the transistor dimensions because of the fundamental thermionic limitation of the steepness of turn-on characteristics, or subthreshold swing 8 , 9 . To enable scaling to continue without a power penalty, a different transistor mechanism is required to obtain sub