Interface traps, correlated mobility fluctuations, and low-frequency noise in metal–oxide–semiconductor transistors

Abstract

Interface traps generally are not considered to be likely sources of low-frequency (LF) noise and/or random telegraph noise (RTN) in metal–oxide–semiconductor (MOS) devices because the longer carrier exchange times of border traps are more consistent with experimental observations. In contrast, correlated mobility fluctuations due to remote Coulomb scattering from charged border traps cannot explain the unexpectedly large LF noise and/or RTN observed in some MOS devices. In this Letter it is proposed that equilibrium fluctuations in interface-trap concentrations caused by hydrogen-induced activation and passivation reactions can lead to enhanced LF noise and RTN. This mechanism adds to other noise sources, including border traps, random dopants, and bulk-Si defect clusters.

Low-frequency noise in nanowires

“…51,71,83 Fluctuations due to single defects become increasingly common in highly scaled devices of each type. 15,53–58,66,74–77,84–90 These results illustrate the diversity of mechanisms that can lead to conductivity fluctuations in metallic and semiconducting NWs.…”

“…In recent decades, metallic and semiconducting nanowires (NWs) have enabled investigations of a wide range of phenomena including Anderson localization, electron–electron interactions, and quantum-mechanical decoherence; 1–23 magnetism, including Aharonov–Bohm oscillations and the Kondo effect; 11,18,23–39 superconductivity, macroscopic quantum tunnelling, and Majorana bound states; 39–50 and low-frequency noise, random-telegraph noise, and universal conductance fluctuations. 51–77…”

“…5–9,12,20 As microelectronic fabrication techniques advanced, NW fabrication techniques evolved from substrate step and templating methods to state-of-the-art lithography capable of producing nanostructures in volume and integrating semiconductor NWs into architectures that facilitate fabrication and measurement. 5–9,12,20,71–77,81,82…”

“…The Dutta–Horn model of thermally-activated 1/ f noise, where f is the frequency, and the number fluctuation model of LF noise in MOSFETs are emphasized. 55,66,73,76 LF noise and RTN of metallic NWs are discussed in Section III; representative results for semiconducting NWs with Si and III–V semiconductor channels are shown in Section IV. Bulk noise persists over large volumes in metallic NWs.…”

“…When contact noise is controlled effectively during device fabrication, near-interfacial oxide traps (border traps) can lead to LF noise and RTN in MOSFETs. 56,66,73,74,76,77,90,107–124 In the Si MOS literature, particularly before the early 1990s, these defects are often erroneously called interface traps (or states). 113,116 This term should be applied only to defects at the interface that are in rapid communication with the channel, typically on ∼μs time scales for Si MOS devices.…”