High Lateral Breakdown Voltage in Thin Channel AlGaN/GaN High Electron Mobility Transistors on AlN/Sapphire Templates

Abstract

In this paper, we present the fabrication and Direct Current/high voltage characterizations of AlN-based thin and thick channel AlGaN/GaN heterostructures that are regrown by molecular beam epitaxy on AlN/sapphire. A very high lateral breakdown voltage above 10 kV was observed on the thin channel structure for large contact distances. Also, the buffer assessment revealed a remarkable breakdown field of 5 MV/cm for short contact distances, which is far beyond the theoretical limit of the GaN-based material system. The potential interest of the thin channel configuration in AlN-based high electron mobility transistors is confirmed by the much lower breakdown field that is obtained on the thick channel structure. Furthermore, fabricated transistors are fully functional on both structures with low leakage current, low on-resistance, and reduced temperature dependence as measured up to 300 °C. This is attributed to the ultra-wide bandgap AlN buffer, which is extremely promising for high power, high temperature future applications.

AlGaN Channel High Electron Mobility Transistors with Regrown Ohmic Contacts

“…Employing AlN as a buffer layer enables it to handle extremely high voltages due to its large electric breakdown field [20,21]. AlN enables it to uniquely combine higher critical electric field [22] and thermal conductivity [23] than those of GaN material. Furthermore, an improved electron confinement within the two-dimensional electron gas (2DEG) can also be expected when using AlN as a buffer layer, which acts as a back barrier.…”

Large-Signal Linearity and High-Frequency Noise of Passivated AlGaN/GaN High-Electron Mobility Transistors

“…Heterostructure field-effect transistor (HFET) technology has become essential in microwave communication systems [ 1 , 2 ]. III-nitride high-electron-mobility transistors (HEMTs) are of significant importance in the development of next-generation power applications [ 3 , 4 , 5 ]. The AlGaN/GaN heterostructure has the advantage of large electron velocity and high breakdown electric field.…”

Editorial for the Special Issue on Wide Bandgap Based Devices: Design, Fabrication and Applications

“…Three papers [ 1 , 2 , 3 ] deal with RF power electronics for future 5G applications and other high-speed high-power applications. Nine of the papers, [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ], explore various designs of wide bandgap high power devices. The remaining papers cover various applications based on wide bandgaps, such as ZnO Nanorods for High Photon Extraction Efficiency of GaN-Based Photonic Emitter [ 13 ], InGaZnO Thin-Film Transistors [ 14 ], Wide Band Gap WO 3 Thin Film [ 15 ], Silver Nanorings [ 16 , 17 ] and InGaN Laser Diode [ 18 , 19 , 20 ].…”

“…Keum et al [ 10 ] investigated the time-dependent dielectric breakdown (TDDB) characteristics of normally-off AlGaN/GaN gate-recessed MISHEMTs submitted to proton irradiation. Abid et al [ 11 ] presented the fabrication of AlN-based thin and thick channel AlGaN/GaN heterostructures that have been regrown by molecular beam epitaxy on AlN/sapphire. A remarkable breakdown field of 5 MV/cm has been observed for short contact distances, which is far beyond the theoretical limit of the GaN-based material system.…”