Noise Characterization

1/f and RTS noise in InGaAs nanowire MOSFETs

“…If the LF noise had arisen from the source/drain resistance instead, SId/Id 2 would have been be independent of A. In contrast to a previous study on highly scaled InGaAs GAA MOSFETs [3], our measurements show that number fluctuations (rather than mobility fluctuations) are the dominant LF noise source, as the normalized drain current noise In equation (1), ox is the oxide capacitance per unit area and λ is the tunneling attenuation length in the gate oxide, given by = ( 4 ℎ √2 * Ф ) −1 [7]. Assuming an effective electron mass of * = 0.23 [8] in Al2O3 and an oxide barrier height of Ф = 2.4 eV [9], the trap density is as low as ~ 9·10 18 cm -3 eV -1 .…”

“…If the trap density close to the gate oxide/channel interface is higher (lower) than that in the interior of the gate oxide, β is larger (smaller) than -1. For a trap density that is uniform in depth, β = -1 [7]. In all our devices, β typically varies between -0.7 and -1.5 when sweeping the gate voltage overdrive from -0.2 V to 0.3 V. This clear gate voltage dependence on β indicates that relatively few traps limit the performance of the devices; otherwise the trap density would be more uniform in depth leading to β = -1 independent of the gate voltage (assuming there are no spatial preferences for the trap formations in the gate oxide).…”

Charge Noise in Organic Electrochemical Transistors

“…Hence, the corresponding voltage noise power spectral density can be obtained via S V ðfÞ ¼ S I sd ðfÞR 2 , where R ¼ 1=G is the channel resistance. S V ðfÞ is the voltage noise when the transistor is current biased and is commonly used to compare the noise of a transistor adjusted to different resistance values via the gate [20,[37][38][39]. α characteristic with α ≈ 1 in the low-frequency range, indicating that there are no single dominant processes taking place at a specific time scale [37].…”

Evaluation of deep levels in In0.53Ga0.47As and GaAs0.5Sb0.5 using low‐frequency noise and RTS noise characterization

“…It is clear that the trend in K f is substantially different among InGaAs, GaAsSb, and heterojunction devices. This difference may suggest that distributed interface states exist at the heterointerfaces of the heterojunction devices, since the Lorentzians that cover a certain energy range in the bandgap can integrate and form an extra noise, which then superimposes on the 1/f background [12]. More detailed investigation of this is the subject of ongoing work using more direct probes of these interface states by DLTS.…”