Improved RF-DC characteristics and reduced gate leakage in GaN MOS-HEMTs using thermally grown Nb₂O₅ gate dielectric

Abstract

This work demonstrates the improvement in DC and RF characteristics and a reduction in the gate leakage current for thermally grown Nb2O5 as a gate dielectric in AlGaN/GaN metal–oxide–semiconductor high electron-mobility transistors (MOS-HEMTs). The MOS-HEMTs with an amorphous 10 nm thick Nb2O5 as the gate dielectric show a reduced gate leakage current of 10-9 A/mm. Nb2O5 thin film creates a tensile strain in the AlGaN layer, enhancing the density of two-dimension electron gas (2-DEG). The performance of the device also improves in terms of saturation drain current, peak transconductance, subthreshold swing, and unity current gain frequency. An increase in the source-to-drain ON/OFF current ratio to 108 and a significant reduction in the subthreshold leakage current by at least two orders of magnitude are measured compared to the control HEMTs.

СИНТЕЗ И ХАРАКТЕРИЗАЦИЯ ТОНКОПЛЕНОЧНЫХ ПОКРЫТИЙ НА ОСНОВЕ Nb2O5-MoN-AlN ПОЛУЧЕННЫХ МЕТОДОМ МАГНЕТРОННОГО НАПЫЛЕНИЯ

“…Также немаловажную роль в определении эффективности повышения прочностных свойств играет вариация компонент составов покрытий или возможность получения покрытий путем варьирования слоев различных компонент, в результате которого получаются многослойные покрытия по типу «сэндвичей». Подобные покрытия обладают повышенной устойчивостью к механическим воздействиям, которое обусловлено граничными эффектами, возникающими при вариации слоев [12,13]. В ряде работ использование подобных структур (многослойных покрытий) позволило получить высокопрочные радиационностойкие покрытия, способные увеличить устойчивость сталей к газовому распуханию [14,15] Определение твердости было осуществлено с применением метода индентирования (в качестве индентера использовалась пирамида Виккерса).…”

Investigation of the Effect of Different SiNx Thicknesses on the Characteristics of AlGaN/GaN High-Electron-Mobility Transistors in Ka-Band

“…For traditional AlGaN/GaN HEMTs, the transconductance (G m ) of the device rapidly decreases after reaching its peak as the gate-source voltage (V GS ) increases, resulting in severe nonlinearity [28]. To improve the DC characteristics of a device, many studies have proposed methods such as modifying the device structure or reducing the gate leakage current to enhance the overall DC and RF performance of the device [29][30][31][32]. However, there is limited literature on improving device performance by increasing the SiN x thickness [33].…”

Identifying nano-Schottky diode currents in silicon diodes with 2D interfacial layers

“…In diode applications, there is usually a tradeoff between layer thickness and series resistance. When using insulating materials, this requires a tunneling layer thickness or low breakdown voltage across the insulator [5,6]. In compound semiconductor transistors, extensive research is underway to develop metal-insulator-semiconductor (MIS) gates with dielectrics such as Al2O3 and SiNx [7] to replace the commonly used Schottky gate diodes.…”