A FinFET with one atomic layer channel

Since its invention in the 1960s, one of the most significant evolutions of metal-oxide-semiconductor field effect transistors (MOS-FETs) would be the three dimensionalized version that makes the semiconducting channel vertically wrapped by conformal gate electrodes, also recognized as FinFET. During the past decades, the width of fin (W$${}_{{\rm{fin}}}$$) in FinFETs has shrunk from about 150 nm to a few nanometers. However, W$${}_{{\rm{fin}}}$$ seems to have been levelling off in recent years, owing to the limitation of lithography precision. Here, we show that by adapting a template-growth method, different types of mono-layered two-dimensional crystals are isolated in a vertical manner. Based on this, FinFETs with one atomic layer fin are obtained, with on/off ratios reaching $$\sim\!\! 10^{7}$$. Our findings push the FinFET to the sub 1 nm fin-width limit, and may shed light on the next generation nanoelectronics for higher integration and lower power consumption. FinFETs are an evolution of metal-oxide-semiconductor field effect transistors (MOSFETs) featuring a semiconducting channel vertically wrapped by conformal gate electrodes. Here, the authors use a two-dimensional semiconductor to push the FinFET width to sub-nm whilst achieving a 107 ON/OFF ratio.