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In0.08Al0.92N/GaN fin-type high-electron mobility transistors (fin-HEMTs) with different gate-to-drain lengths (${L} _{\text {gd}}$) are fabricated and characterized by dc and low-frequency noise (LFN) measurements. The fabricated device with the largest ${L} _{\text {gd}}$ exhibits the degradation of the maximum drain current and transconductance with a positive shift of the threshold voltage. LFN measurements of the In0.08Al0.92N/GaN fin-HEMTs reveal clear 1/ ${f}$ behavior of the noise spectra, and the minimum value is observed in the device at ${L} _{\text {gd}} = {20}\,\,\mu \text{m}$. The devices with smaller ${L} _{\text {gd}}$ follow a carrier number fluctuation noise model owing to electron trapping/detrapping into the In0.08Al0.92N barrier layer from the 2-D electron gas (2DEG) channel. In contrast, the device with the largest ${L} _{\text {gd}}$ shows correlated mobility fluctuations due to the large 2DEG mobility fluctuations in the large access area. [ABSTRACT FROM AUTHOR]

Superior device characteristics have been demonstrated with a novel Al(In)N/GaN-based steep fin-type high electron mobility transistor (HEMT) with a fin width ( W\mathrm{ fin} ) of 120 nm, a fin height ( H\mathrm{ fin}) of 250 nm, and a gate length ( LG ) of 200 nm. The proposed device achieved very low drain leakage ( I\mathrm{ off}) < 8 \times 10^{-8} A/mm at 7 V and < 1 \times 10^-6 A/mm at 100 V, which is four orders of improvement over I\mathrm{\scriptscriptstyle OFF} of conventional Al(In)N/GaN HEMTs. In addition, the device exhibits a high ON-state current ( I\mathrm{\scriptscriptstyle ON}) of 1.12 A/mm, a steep sub-threshold swing ( $S$ ) of 63 mV/decade, a low drain-induced barrier lowering of 18.5 mV/V, and a high power-gain cutoff frequency ( f_{T} ) of 21 GHz. [ABSTRACT FROM PUBLISHER]

In this paper, we propose an AlGaN/GaN high electron mobility transistor (HEMT)-based biosensor for the detection of C-reactive protein (CRP) using a null-balancing circuit. A null-balancing circuit was used to measure the output voltage of the sensor directly. The output voltage of the proposed biosensor was varied by antigen-antibody interactions on the gate surface due to CRP charges. The AlGaN/GaN HFET-based biosensor with null-balancing circuit applied shows that CRP can be detected in a wide range of concentrations, varying from 10 ng/mL to 1000 ng/mL. X-ray photoelectron spectroscopy was carried out to verify the immobilization of self-assembled monolayer with Au on the gated region.

Vertical-channel gallium nitride (GaN) junctionless nanowire transistor (JNT) has been designed and characterized by technology computer-aided design (TCAD) simulations. Various characteristics such as wide bandgap, strong polariztion field, and high electron velocity make GaN one of the attractive materials in advanced electronics in recent times. Nanowire-structured GaN can be applicable to various transistors for enhanced electrical performances by its geometrical feature. In this paper, we analyze the direct-current (DC) characteristics depending on various channel doping concentrations (N(ch)) and nanowire radii (R(NW)). Furthermore, the radio-frequency (RF) characteristics under optimized conditions are extracted by small-signal equivalent circuit modeling. For the optimally designed vertical GaN JNT demonstrated on-state current (I(on)) of 345 μA/μm and off-state current (I(off)) of 3.7 x 10(-18) A/μm with a threshold voltage (V(t)) of 0.22 V, and subthreshold swing (S) of 68 mV/dec. Besides, f(T) and f(max) under different operating conditions (gate voltage, V(GS)) have been obtained.