Effects of Carrier Trapping and Noise in Triangular-Shaped GaN Nanowire Wrap-Gate Transistor

The most widely used nanowire channel architecture for creating state-of-the-art high-performance transistors is the nanowire wrap-gate transistor, which offers low power consumption, high carrier mobility, large electrostatic control, and high-speed switching. The frequency-dependent capacitance and conductance measurements of triangular-shaped GaN nanowire wrap-gate transistors are measured in the frequency range of 1 kHz-1 MHz at room temperature to investigate carrier trapping effects in the core and at the surface. The performance of such a low-dimensional device is greatly influenced by its surface traps. With increasing applied frequency, the calculated trap density promptly decreases, from 1.01 × 10¹³ cm^-2 eV^-1 at 1 kHz to 8.56 × 10¹² cm^-2eV^-1 at 1 MHz, respectively. The 1/<i>f</i>-noise features show that the noise spectral density rises with applied gate bias and shows 1/<i>f</i>-noise behavior in the accumulation regime. The fabricated device is controlled by 1/<i>f</i>-noise at lower frequencies and 1/<i>f</i>²-noise at frequencies greater than ~ 0.2 kHz in the surface depletion regime. Further generation-recombination (G-R) is responsible for the 1/<i>f</i>²-noise characteristics. This process is primarily brought on by electron trapping and detrapping via deep traps situated on the nanowire's surface depletion regime. When the device works in the deep-subthreshold regime, the cut-off frequency for the 1/<i>f</i>²-noise characteristics further drops to a lower frequency of 30 Hz-10⁴ Hz.