Electrical properties of (11-22) Si:AlGaN layers at high Al contents grown by metal-organic vapor phase epitaxy

Abstract

In this work, the growth and conductivity of semipolar AlxGa1-xN:Si with (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) orientation is investigated. AlxGa1-xN:Si (x = 0.60 ± 0.03 and x = 0.80 ± 0.02) layers were grown with different SiH4 partial pressures and the electrical properties were determined using Hall measurements at room temperature. The aluminum mole fraction was measured by wavelength dispersive X-ray spectroscopy and X-ray diffraction and the Si-concentration was measured by wavelength dispersive X-ray spectroscopy and secondary ion mass spectroscopy. Layer resistivities as low as 0.024 Ω cm for x = 0.6 and 0.042 Ω cm for x = 0.8 were achieved. For both aluminum mole fractions the resistivity exhibits a minimum with increasing Si concentration which can be explained by compensation due to formation of cation vacancy complexes at high doping levels. The onset of self-compensation occurs at larger estimated Si concentrations for larger Al contents.

Quantification of Trace-Level Silicon Doping in AlxGa1–xN Films Using Wavelength-Dispersive X-Ray Microanalysis

“…More details on the growth of the Al x Ga 1-x N:Si layers from the Tyndall Institute are given elsewhere (Li et al, 2013;Dinh et al, 2016aDinh et al, , 2016bPampili et al, 2018;Spasevski et al, 2021). Samples labeled TS are Al x Ga 1-x N layers with various AlN contents and crystal polarities grown at Technische Universität Berlin (Knauer et al, 2013;Kusch et al, 2014;Mehnke et al, 2016;Foronda et al, 2020). The "blank" Al x Ga 1-x N TS5541 was grown with no Si doping and quickly shipped in a sealed container filled with N 2 gas in order to minimize contamination and on receipt it was immediately placed under vacuum within the EPMA chamber.…”

“…It is challenging to effectively dope Al x Ga 1– x N, with Si and Mg at such high AlN contents because as the bandgap increases the ionization energies also increase. At the same time, a very high Si doping concentration is needed to achieve low resistivity Al x Ga 1– x N layers (Mehnke et al, 2016; Foronda et al, 2020).…”

Assessing the Impact of Secondary Fluorescence on X-Ray Microanalysis Results from Semiconductor Thin Films

“…Therefore, prior to device design and manufacture, the materials are generally characterized in thicker layers. These samples consist of much thicker layers (100 s to 1,000 s nm) more suited for determination of elemental composition by X-ray analysis (Martin et al, 2002; Bejtka et al, 2008; Foronda et al, 2020).…”

“…The optical properties of a material can therefore be tailored once a reliable growth method is established. WDX has previously been used to characterize Al x Ga 1− x N (Foronda et al, 2020; Spasevski et al, 2021); however, it is unknown to what degree secondary fluorescence may have had an impact on these results. Another important III-nitride alloy is In x Al 1− x N, which is usually grown on GaN substrates for low InN fractions.…”

Study on Ablation Characteristics of Femyosecond Laser Nanoscale Processing for Aluminum Nitride and LeadZirconate Titanate Ceramics

“…AlN is a wide band gap semiconductor material. Its applications include radio frequency filters [5], ultraviolet (UV) solid state light sources [6], acoustic resonators [5], and photodetectors [7].…”