Low-frequency noise in contact and channel regions of ambipolar InAs nanowire transistors

Semiconductor nanowires are promising candidates for nanoelectronic applications such as high-speed electronics, chemical sensors, and transparent electronics. However, practical application of these devices is hindered by the excessive levels of low-frequency (1/f) noise. The general physical model of 1/f noise stems from carrier interactions with the surface oxide along the channel, but the problem is exacerbated in nanowires because of their high surface-to-volume ratio. However, other mechanisms may also contribute to carrier fluctuations leading to higher levels of noise, such as fluctuations in the metal-semiconductor source and drain contacts. Understanding the physics and contributions from the different regions is key to optimizing noise in nanowire devices, but few studies have distinguished between these mechanisms.