MBE growth of cubic AlN on 3C?SiC substrate
نویسندگان
چکیده
We present our recent results on the growth of cubic AlN (001) layers by plasma assisted molecular beam epitaxy (PAMBE) using freestanding 3C-SiC (001) substrate. For high-quality c-AlN layers reflection high-electron energy diffraction (RHEED) patterns in all azimuths show RHEED patterns of the cubic lattice, hexagonal reflections are absent. Highresolution X-ray diffraction (HRXRD) measurements confirm the cubic structure of the c-AlN layers with a lattice parameter of 4.373 Å. Atomic force microscopy (AFM) scans show an atomically smooth surface with a roughness of 0.2 nm RMS. Ellipsometry studies yield the dielectric function (DF) of c-AlN from 1 to 10 eV. The direct gap is determined with 5.93 eV at room temperature, while the indirect one is below 5.3 eV (onset of adsorption). The high-energy part of the DF is dominated by two transitions at 7.20 and 7.95 eV attributed to critical points of the band structure.
منابع مشابه
Effect of nanoscale surface morphology on the phase stability of 3C-AlN films on Si„111..
In this work, we report on the stabilization of 3C-AlN polytype by molecular-beam epitaxy sMBEd on 3C-SiC/Sis111d pseudosubstrates. The main purpose of the present studies is to analyze the mechanisms forcing the epitaxy of the 3C-AlN at typical MBE conditions. The forces driving the cubic polytype formation have been considered including supersaturation, macroscopic stress, interfacial energy,...
متن کاملGrowth of Highly C-axis Oriented Aln Films on 3c-sic/si Substrate
For the first time, highly c-axis oriented heteroepitaxial AlN thin films have been successfully grown on epitaxial 3C-SiC films on Si (100) substrates. The AlN films deposited by the AC reactive magnetron sputtering at temperatures of approximately 300-450 °C were characterized using the scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and transmissio...
متن کاملAdvances in the molecular-beam epitaxial growth of artificially layered heteropolytypic structures of SiC
The controlled growth of SiC heteropolytypic structures consisting of hexagonal and cubic polytypes has been performed by solid-source molecular-beam epitaxy. On on-axis substrates, 4H/3C/4H–SiC~0001! and 6H/3C/6H–SiC~0001! structures were obtained by first growing the 3C–SiC layer some nanometer thick at lower substrate temperatures (T51550 K) and Si-rich conditions and a subsequent growth of ...
متن کاملSublimation Growth and Performance of Cubic Silicon Carbide
Current advancement in electronic devices is so rapid that silicon, the semiconductor material most widely used today, needs to be replaced in some of the fields. Silicon carbide (SiC) is a wide band gap semiconductor satisfying requirements to replace silicon in devices operating at high power and high frequency at elevated temperature, and in harsh environments. Hexagonal polytypes of SiC, su...
متن کاملTheoretical Analysis of SAW Propagation in 3C-SiC/c-AlN
The anisotropic materials as the acoustic wave propagating medium introduce the dependence of the phase velocity on the wave propagation direction, as opposed to the isotropic counterparts; in addition, the profile of the particle displacement components can be quite different, depending on the crystal type and propagation direction. The propagation of surface and bulk acoustic waves (SAWs and ...
متن کامل