Growth of AlGaN/InGaN/GaN Heterostructure on AlN Template/Sapphire

Abstract

GaN films are grown directly on AlN templates/sapphire substrates without using low‐temperature (LT) buffer layers by metalorganic chemical vapor deposition. AlN templates are complimentarily deformed at the initial growth of GaN, adjusting the a‐lattice constant and tilting crystal orientation slightly. Compared with the film on sapphire substrates using an LT buffer layer, the GaN on the AlN template forms a smoother surface and has better crystalline quality after a shorter growth time at a lower temperature. Higher‐quality InGaN films on the GaN/AlN template are subsequently grown to optimize the thickness exhibiting the minimum Urbach energy which is evaluated by photothermal deflection spectroscopy. A high‐quality AlGaN/InGaN heterostructure is fabricated in which the Shubnikov–de Haas oscillation can be clearly observed from the electron gas of the InGaN channel at the interface.

Fabrication of AlGaN/GaN heterostructures on halide vapor phase epitaxy AlN/SiC templates for high electron mobility transistor application

“…The interface of AlGaN/InGaN was good enough to exhibit Shubnikov-de Haas (SdH) oscillations from the 2D electron gas (2DEG) of the InGaN channel. 15) In this study, we developed a method for growing GaN films on an HVPE AlN template/SiC substrate, and investigated the behavior of the film growth to obtain a thin GaN channel layer suitable for HEMTs. The properties of the AlGaN/GaN heterostructure on the AlN template were evaluated with respect to the transport of electrons in a 2DEG in a magnetic field.…”