The effect of GaN thickness inserted between two AlN layers on the transport properties of a lattice matched AlInN/AlN/GaN/AlN/GaN double channel heterostructure

Abstract

One AlInN/AlN/GaN single channel heterostructure sample and four AlInN/AlN/GaN/AlN/GaN double channel heterostructure samples with different values of the second GaN layer were studied. The interface profiles, crystalline qualities, surface morphologies, and dislocation densities of the samples were investigated using high resolution transmission electron microscopy, atomic force microscopy, and high-resolution X-ray diffraction. Some of the data provided by these measurements were used as input parameters in the calculation of the scattering mechanisms that govern the transport properties of the studied samples. Experimental transport data were obtained using temperature dependent Hall effect measurements (10-300 K) at low (0.5 T) and high (8 T) magnetic fields to exclude the bulk transport from the two-dimensional one. The effect of the thickness of the second GaN layer inserted between two AlN barrier layers on mobility and carrier concentrations was analyzed and the dominant scattering mechanisms in the low and high temperature regimes were determined. It was found that Hall mobility increases as the thickness of GaN increases until 5 nm at a low temperature where interface roughness scattering is observed as one of the dominant scattering mechanisms. When GaN thicknesses exceed 5 nm, Hall mobility tends to decrease again due to the population of the second channel in which the interface becomes worse compared to the other one. From these analyses, 5 nm GaN layer thicknesses were found to be the optimum thicknesses required for high electron mobility.

Electron transport in a coupled GaN/AlN/GaN channel of nitride HFET

“…However, it might not be practical to heat the electrons sufficiently in order to reduce their peak density to the resonance one without damaging the sample. An alternative solution which does not require electric field to spread the electron distribution is to diminish the 3D density in composite channel structures with a camelback electron density profile [21][22][23][24][25][26].…”

The enhancement of the output characteristics in the GaN based multiple‐channel planar Gunn diode

“…As a promising candidate for GaN‐based heterostructure, AlInN/GaN heterostructure has attracted intense interest since firstly proposed by Kuzmík in the last 10 years . In lattice‐matched Al 0.83 In 0.17 N/GaN based HEMTs, the polarization charge is completely determined by spontaneous polarization since the structure is free of strain; therefore the AlInN/GaN HEMTs exhibit polarization‐induced charge and drain current several times higher than the conventional AlGaN/GaN structure, which makes the AlInN/GaN HEMT more promising for high power and high frequency transit or operation . In this paper, a substantial investigation into AlGaN/GaN multi‐channel HEMT‐like planar Gunn diode by a tool of TCAD (Silvaco‐ATLAS) has been proposed, aimed at demonstrating its great advantages in improving the diode performance over the single channel AlGaN/GaN and the AlInN/GaN HEMT‐like planar Gunn diode.…”