The effect of gate leakage on the noise figure of AlGaN/GaN HEMTs

Abstract

Abstract-The effect of gate leakage on the noise figure of AlGaN/GaN high electron mobility transistor (HEMTs) is explored. It is shown that these devices have a sizable amount of gate leakage that cannot be ignored when measuring their noise performance. Measurements across a single sample have more than 1 dB of variation in minimum noise figure. We will show this variation is because of gate leakage. A modified van der Ziel model is used to predict this large variation and allows easy noise figure prediction of HEMT and MESFET devices.Index Terms-AlGaN, GaN, gate leakage, high electron mobility transistor (HEMT), noise figure, van der Ziel.

The impact of post gate annealing on microwave noise performance of AlGaN/GaN HEMTs

“…To analyze the improvement of microwave noise performance in the AlGaN/GaN HEMTs before and after annealing, a model presented in [12] which includes a shot noise source for gate leakage current is employed. The overall microwave noise of AlGaN/GaN HEMTs is decomposed to thermal noise from parasitic resistances (E r ), gate leakage current noise (I g ) and drain current noise (I d ).…”

“…Rs ; R g , R i , R s , g m and C gs are circuit elements in small-signal equivalent circuit [12]; x is the angular frequency; R opt and X opt are the optimum source impedance, and I gs is the gate leakage current. The significant gate leakage current decrease after annealing lowers the third term in Eq.…”

Reduction of current collapse in AlGaN/GaN MISHEMT with bilayer SiN/Al2O3 dielectric gate stack

“…Various surface passivation methods, especially passivation through PECVD SiN [3] have helped in mitigating the current collapse phenomenon. Secondly, the high gate leakage currents that the conventional GaN HEMTs with Schottky metal gates suffer from, that limits the gate voltage swing and thus affecting the maximum output power as well the microwave performance [4,5]. To reduce the gate leakage currents, researchers have tried various gate dielectrics such as SiO 2 [6,7], SiN [8,9], Al 2 O 3 [10], MgO [11], Sc 2 O 3 [12], and ZrO 2 [13].…”

Characterization of high-frequency noise performance of GaN double heterojunction HEMT

“…Until now, research effects, including modeling of noise, improvement of process, and advanced epitaxial layer structure, have been reported to improve the microwave performance of GaN-based HEMT [7][8][9][10]. GaN double heterojuction HEMT (DH-HEMT) has been studied in the application of high output power devices [11][12][13][14].…”