Deep-level trapping centers in heterostructures for GaN field-effect transistors

Abstract

Structural and electrophysical properties of heteroepitaxial gallium nitride layers on a sapphire substrate that are grown via the molecular beam epitaxy (MBE) method are studied. The parameters of deep-level trapping centers are determined by the method of the thermostimulated capacitor discharge; the degree of perfection of the film and substrate are determined by the two-crystal X-ray spectrometry method. The following structures are studied: i-GaN (1–2 µm)/GaN 〈Si〉(0.1−0.4 µm) and multilayer structures (Al0.3Ga0.7N-GaN-Al0.3-Ga0.7N-GaN-Al2O3) grown via the MBE method on a sapphire substrate. The effect of reactive ion etching on the energy spectrum of deep-level trapping centers in gallium nitride is studied. The obtained results are used to calculate the energy spectrum of defects in gallium nitride structures.