High quality InAlN/GaN heterostructures grown on sapphire by pulsed metal organic chemical vapor deposition

Effects of AlN interlayer on the transport properties of nearly lattice-matched InAlN/GaN heterostructures grown on sapphire by pulsed metal organic chemical vapor deposition

“…Compared to the previous results reported in Ref. 17, the measured sheet carrier density presented in this work are rather low, which may be caused by an inadvertent parasitic GaN layer formed in the InAlN barrier due to a minor Ga incorporation from the residual TMGa source within the system during the growth interruption [22]. It is a part of our on-going work to examine the InAlN barriers with respect to the presence of Ga.…”

“…The AlN interlayer thickness was estimated from the growth rates and confirmed by spectroscopic ellipsometry measurements [17]. As a unique variable, the growth time, including 0, 6, 12, 18, 24, and 30 s, was used for the AlN interlayer, corresponding to the different thickness of about 0, 0.4, 0.8, 1.2, 1.6, and 2.0 nm, respectively.…”

“…In this work, InAlN barriers for different samples were grown under same growth conditions as shown in Ref. [17]. So the indium content for the different samples was nearly identical.…”

“…Nevertheless, the use of InAlN still proves to be a remarkable choice for HEMT fabrication; therefore, considerable progress has been made after the original proposal [13][14][15][16]. In this work, different from the reported growth methods such as molecular beam epitaxy (MBE) or traditional metal organic chemical vapor deposition (MOCVD), we adopted pulsed metal organic chemical vapor deposition (PMOCVD) for InAlN epitaxial growth to achieve excellent results [17]. Particularly, the effects of AlN interlayer thickness on the transport properties of nearly lattice-matched InAlN/GaN heterostructures grown on (0001) sapphire substrates are investigated in order to obtain the optimum thickness of AlN interlayer.…”

Importance of growth temperature on achieving lattice-matched and strained InAlN/GaN heterostructure by plasma-assisted molecular beam epitaxy

“…However, in the recent past, impressive efforts have been made in the developments of InAlN-GaN heterostructures using both MBE and MOCVD. [6][7][8] The major challenge in realizing high quality InAlN epitaxial layer is to achieve crack-free, highly homogeneous composition with smooth morphology. Besides, the compositional induced structural variations of InAlN layers have a strong impact on electrical and optical properties, and thus on the device performance.…”