Buffer-Related Degradation Aspects of Single and Double-Heterostructure Quantum Well InAlN/GaN High-Electron-Mobility Transistors

Abstract

We experimentally prove the viability of the concept of the double-heterostructure quantum well InAlN/GaN high-electron-mobility transistor (HEMT) for the device higher robustness and reliability. In the single quantum well InAlN/GaN HEMTs, the intrinsic channel resistance increases by 300% after 1 h off-state stress; much less degradation is observed in the double-heterostructure device with an AlGaN back barrier. Physicsbased device simulation proves that the back barrier blocks the rate of carrier injection into the device buffer. However, whatever the quantum well design is, the energy of the injected electrons in the buffer of InAlN/GaN-based HEMTs is higher than that in the buffer of AlGaN/GaN HEMTs. This energy may be sufficient for releasing hydrogen from GaN point defects.

Evolution of Deep Traps in GaN‐Based RF High Electron Mobility Transistors under High Voltage OFF‐State Stress

“…[18,23] However, such degradation only occurs on a small portion of drain-side of the gate edge, as verified by emission microscope (EMMI) images comparison shown in though it does insignificant effect on the reverse gate leakage, may also occur under the high voltage OFF-state stress. [22][23][24] Advanced characterization techniques should be explored to distinguish the traps from the AlGaN barrier or the GaN buffer in the AlGaN/GaN HEMTs.…”

“…It is demonstrated that inverse piezoelectric-induced degradation can be alleviated by reducing Al content in the AlGaN barrier, by optimizing field plate to counterbalance the strain, and even by introducing an AlGaN back barrier. [7][8][9][10] Nevertheless, reliability of GaN RF HEMTs at stressing voltage higher than 100 V remains to be investigated.…”

Degradation Study of Single and Double-Heterojunction InAlN/GaN HEMTs by Two-Dimensional Simulation

“…Three orders of magnitude lower gate and drain off-state leakage currents were observed in DHQW compared to those of SQW HEMTs [10]. The gate length is 250nm, and the gate-to-drain distance is 1.5μm.…”

Hot electron induced non-saturation current behavior at high electric field in InAlN/GaN heterostructures with ultrathin barrier

“…On one hand, compared to AlGaN, the material quality of InAlN still need to be improved due to the different optimized growth conditions of InN and AlN and the expected large immiscibility gap of the ternary alloy. Thus, there are large density of defects which may correlate to the problem of more serious degradation of the InAlN/GaN HEMTs678. On the other hand, the larger spontaneous polarization in InAlN/GaN heterostructures contributes to much higher two-dimensional electron gas (2DEG) density in the lattice-matched In 0.18 Al 0.82 N/GaN system with thin barrier layer910.…”

“…Although the higher electron velocity is benefit to high frequency devices, the hot-electron temperature ( T e ) in InAlN/GaN is much higher than that in AlGaN/GaN. For example, Kuzmik et al reported that T e in InAlN/GaN may reach as high as 30000 K615. Considering the hot electrons with higher energy and facing larger defects density, the transport characteristics of InAlN/GaN at high electric field are more complex and lack of systematic studies, compared with that of AlGaN/GaN.…”