On the Characteristics and Spatial Dependence of Channel Thermal Noise in Nanoscale Metal–Oixde–Semiconductor Field Effect Transistors

Abstract

The physical origin of the channel thermal noise in nanoscale RF metal–oxide–semiconductor field effect transistors (MOSFETs) is characterized based on an analytical noise model, which takes into account velocity saturation, channel length modulation, and carrier heating effect. These short channel effects increase the channel thermal noise compared with predicted noise from long-channel theory. Among the three effects, the channel length modulation is found to be the most important short channel effect on the channel thermal noise modeling. In addition, spatial distribution of the channel thermal noise is analyzed by using impedance field method. From this analysis, it is identified that the channel thermal noise is dominated by source side noise contributions.

Physics-Informed Neural Network for High Frequency Noise Performance in Quasi-Ballistic MOSFETs

“…For decreasing channel length, as expected, the drain current noise of Equation ( 8) increases, while the induced gate noise of Equation ( 11) and the correlation noise of Equation ( 12) decrease owing to the cubic and quadratic dependence of I d , respectively. This is consistent with other noise models and measured results [2][3][4][5][6][7].…”

“…The RBF-IANN consists of the same structure as the RBF-DANN in the neural network. Note that the RBF-IANN has an input parameter of the normalized spatial distribution of the local current noise source x/L, incorporating the physical origin of the high frequency [7]. Numerical calculations are performed with v sat = 0.9 × 10 7 cm/s, k bulk = 1.2, T = 300 K, µ e f f = 550 cm 2 /Vs.…”

“…In highfrequency applications, the noise characteristics of the device are very important because they determine the noise performance of the low-noise amplifier used in the front-end receiver and the overall receiver. Therefore, the accurate and physics-based modeling of the high-frequency noise of modern CMOS devices is essential [3][4][5][6][7].…”

“…The HF noise sources in MOSFETs include the thermal drain current noise, due to the channel resistance, giving rise to the induced gate noise and the correlation noise [2][3][4][5][6][7]. In the quasi-ballistic regime, with the channel length comparable to the mean free path length of carriers, there is a tunneling current and its shot noise through the source-todrain (SD) potential barrier [8][9][10][11][12][13][14][15][16][17][18].…”

Accurate Channel Thermal Noise Modeling in BSIM4

“…Then, excess noise factor NTNOI is expressed as NTNOI = (L eff /L c ) 2 . This result is in accordance with the result of [6], which showed that the channel-length modulation is critical short-channel effect to explain excess channel thermal noise in short-channel MOSFET. L c can be obtained from the result of [7, eq.…”