Effects of dissipative substrate on the performances of enhancement mode AlInN/GaN HEMTs

Abstract

AlInN/GaN high electron mobility transistors (HEMTs) exhibit numerous advantages compared to other known semiconductor devices. However, it is more difficult to realize the enhancement mode (E-mode) HEMTs of AlInN/ GaN than those of the AlGaN/GaN heterostructure, because of the higher 2-dimensional electron gas density at the AlInN/GaN interface. In this work, using simulations, it is shown that the E-mode can be achieved in AlInN/ GaN HEMTs by tuning the thickness of the AlInN barrier layer to less than 1.14 nm in our investigated structure. Based on the E-mode structure, the device performance stability of Al 0.83 In 0.17 N/GaN HEMTs with different heat dissipative substrates was evaluated to explore their effect on the suppression of the self-heating behavior. The DC behavior, device temperature, lattice temperature distribution, current cutoff frequency ( f T ), unilateral powergain-cutoff frequency ( f max ), and transient response were investigated comparatively. The results indicate that the AlInN/GaN HEMTs with a free-standing GaN substrate exhibit the best performance characteristics, ie, lowest lattice temperature, highest f T , and fastest transient response, in comparison with those using the flip-chip substrate and sapphire substrate. Our simulation results suggest that the free-standing GaN substrate can significantly improve the thermal stability and other basic performance characteristics of the E-mode AlInN/GaN HEMTs.

Optimization based on electro-thermo-mechanical modeling of the high electron mobility transistor (HEMT)

“…Gallium nitride (GaN) is characterized by high mobility, a very high electric breakdown field and high thermal conductivity which is a great advantage compared to other types of transistor [1,2]. Thanks to these and other characteristics, these transistors are used in several highfrequency and high-temperature applications [3,4], such as, telecommunication, electronic warfare (military field) and airborne systems [5,6], etc. HEMT has also been used in several systems such as high power amplifiers, radars and satellites, it is also found in radio frequency sensors and devices [7].…”

Electrothermal Reliability of the High Electron Mobility Transistor (HEMT)

“…Gallium nitride GaN is characterized by high mobility, very high electrical breakdown field and high thermal conductivity [5,6]. Thanks to these characteristics, these components have been used in different high-temperature and high-frequency applications [7,8], such as airborne systems, telecommunication and electronic warfare [9,10]. HEMT has also been used in several systems such as high-power amplifiers, satellites and radars [11].…”