Thermal effect of roughness in silicon field-effect GAA nanotransistors

Scaling of field-effect transistors requires a more thorough study of degradation effects, one of which is the uneven boundary of the transistor's working area. In addition to classical carrier scattering, a promising transistor architecture, a silicon field–effect GAA nanotransistor with an unalloyed cylindrical working area, exhibits abnormal thermal conductivity of the working area. Using perturbation theory, the effect of the roughness of the boundary of the transistor's working area on its thermal conductivity was investigated and the effect of roughness parameters on the switching current in a nanotransistor with a working area length of 25 nm was investigated. The roughness model is set by two parameters: the correlation length Λ (values of 10 nm and 20 nm) and the standard deviation Δ (range from 0.3 to 0.9 nm). The results of the statistical analysis show that there is a significant difference in current degradation depending on the correlation length. As the RMS deviation increases, the differences in the switching currents increase and at maximum Δ, they differ significantly from the original value: 5.2 % at 10 nm and 11.2 % at 20 nm. From the results obtained, it can be concluded that for small Λ, the dependence of the switching current on the RMS deviation scales to Λ2, i.e., with a decrease Λ, this dependence becomes close to the form ~-Δ2. At high Λ, there is a decrease in the steepness of the dependence of the switching current on Δ up to close to linear.