AlGaN/InGaN/GaN Double Heterostructure Field-Effect Transistor

Abstract

Novel, current collapse free, double heterostructure AlGaN/InGaN/GaN field effect transistors (DHFETs) are fabricated on the insulating SiC substrates. The simulations show that a combined effect of the bandgap offsets and polarization charges provides an excellent 2D carrier confinement. These devices demonstrate output RF powers as high as 4.3 W/mm in CW mode and 6.3 W/mm in the pulsed mode, with the gain compression as low as 4 dB.

Very high channel conductivity in low-defect AlN/GaN high electron mobility transistor structures

“…3͒ and AlInN/GaN, 4 have also been investigated in response to theoretical predictions of higher performance devices. 5,6 Recently, the insertion of a thin ͑ϳ1 ML͒ film of AlN in the HEMT structure has been shown to improve the device performance by increasing the two dimensional electron gas ͑2DEG͒ confinement and reducing alloy scattering. [7][8][9] However, much less work has been done on AlN/GaN heterostructure for HEMT devices mainly due to the difficulty in growing high-quality AlN barrier layers on GaN by either metal organic chemical vapor deposition 10 ͑MOCVD͒ or molecular beam epitaxy ͑MBE͒.…”

AlGaN/GaN/InGaN/GaN DH-HEMTs with an InGaN notch for enhanced carrier confinement

“…However, a high Al composition in the AlGaN buffer layer is still difficult to achieve. Simin et al has implemented AlGaN/InGaN/GaN HEMTs and MOSHFETs [11], [12] in which InGaN has been used as the channel material which is confined from both sides by AlGaN and GaN. However, it is challenging to grow cluster-free high-mobility InGaN layer.…”

“…However, it is challenging to grow cluster-free high-mobility InGaN layer. The highest 2-DEG mobility reported in the AlGaN/InGaN/GaN DH-HEMTs is 730 cm V s [11], [12], significantly lower than that achieved in conventional AlGaN/GaN HEMTs. In this letter, we report an AlGaN/GaN/InGaN/GaN DH-HEMT that features an InGaN-notch in the channel region.…”

Simulation of gate lag and current collapse in gallium nitride field-effect transistors

“…Also, there is experimental evidence that the incorporation of indium in the channel, forming a double heterostructure FET (DHFET), leads to significantly smaller collapse or gate lag. 7 To verify our model on DH-FET, we also compared results from numerical simulations of the model with gate-edge traps where In was incorporated in the channel to form the desired conduction band barrier. Figure 4 plots the resulting normalized drain current as a function of time for three different In mole fractions: 0%, 2%, and 5%, where the collapse clearly decreases as the mole fraction increases.…”