Performance of ring oscillators composed of gate-all-around FETs with varying numbers of nanowire channels using TCAD simulation

In this paper, we investigate the performance of ring oscillators composed of gate-all-around (GAA) silicon nanowire (NW) field-effect transistors (FETs) with four different numbers of NW channels, for sub-10-nm logic applications. Our simulations reveal that ring oscillators with double, triple, and quadruple NW channels exhibit improvements of up to 50%, 85%, and 97%, respectively, in the oscillation frequencies (f_osc), compared to a ring oscillator with a single NW channel, due to the large drive current, in spite of the increased intrinsic capacitance of a given device. Moreover, our work shows that the f_osc improvement ratio of the ring oscillators becomes saturated with triple NW channels with additional load capacitances of 0.1 fF and 0.01 fF, which are similar to, or less than the intrinsic device capacitance (∼0.1 fF). Thus, our study provides an insight for determining the capacitive load and optimal number of NW channels, for device development and circuit design of GAA NW FETs.     

Synthesis and characterization of silanized-SiO2/povidone nanocomposite as a gate insulator: The influence of Si semiconductor film type on the interface traps by deconvolution of Si2s

The polymer nanocomposite as a gate dielectric film was prepared via sol-gel method. The formation of cross-linked structure among nanofillers and polymer matrix was proved by Fourier transform infrared spectroscopy (FT-IR). Differential thermal analysis (DTA) results showed significant increase in the thermal stability of the nanocomposite with respect to that of pure polymer. The nanocomposite films deposited on the p- and n-type Si substrates formed very smooth surface with rms roughness of 0.045 and 0.058 nm respectively. Deconvoluted Si_2s spectra revealed the domination of the SiOH hydrogen bonds and SiOSi covalence bonds in the structure of the nanocomposite film deposited on the p- and n-type Si semiconductor layers respectively. The fabricated n-channel field-effect-transistor (FET) showed the low threshold voltage and leakage currents because of the stronger connection between the nanocomposite and n-type Si substrate. Whereas, dominated hydroxyl groups in the nanocomposite dielectric film deposited on the p-type Si substrate increased trap states in the interface, led to the drop of FET operation.