The impact of active layer thickness on low-frequency noise characteristics in InZnO thin-film transistors with high mobility

Abstract

We investigated low-frequency noise (LFN) characteristics in passivated InZnO thin-film transistors with various active layer thicknesses. These LFNs are matched to the mobility fluctuation model [F. N. Hooge, IEEE Trans. Electron Devices 41, 1926 (1994)]. According to this model, the Hooge's parameter (alpha(H)) is significantly increased as the active layer thickness is decreased. By plotting the alpha(H) with the effective mobility (mu(eff)), we found that the alpha(H) is proportional to the mu(-1)(eff). This indicates that the mobility fluctuation by the impurity scattering is significantly increased as the active layer thickness is decreased, and that is the main origin of the LFN increments in the thinner active-layer-thickness devices. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4705406]