Structural analysis of N‐polar AlN layers grown on Si (111) substrates by high resolution X‐ray diffraction

Abstract

Crack‐free high quality N‐polar AlN epitaxial layers were grown on Si (111) substrates by plasma‐assisted molecular beam epitaxy in the temperature range of 780–880 °C. The streaky 1×3 reflection high energy electron diffraction pattern was observed at room temperature for all AlN samples indicating N‐polarity of epilayers. The polarity of samples was also confirmed by KOH etching studies. Structural properties of as‐grown samples were carried out by high resolution X‐ray diffraction, scanning electron microscopy, and atomic force microscopy. The Williamson‐Hall plots of the rocking curves widths were employed in order to study the mosaicity, dislocation density, and level of stress as a function of growth temperature. The 250 nm thick AlN sample grown at 830 °C yields the best crystalline quality, smooth surface morphology, and smallest root mean square roughness. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Band Offset Measurements in Atomic-Layer-Deposited Al2O3/Zn0.8Al0.2O Heterojunction Studied by X-ray Photoelectron Spectroscopy

“…1b at 2 θ = 32.6°, 33.2°, 35.4°, 35.9°, 38.8°, 39.2°, and 42.8° in the diffractograms that arise from the Si substrate itself are also observed. These unknown peaks may be related to the process conditions for producing crystalline silicon and are observed in previous work [ 27 , 28 ]. Except for diffraction peaks from the Si substrate, no other diffraction peaks from the Zn x Al 1- x O ( x ≤ 0.9) samples are detected.…”

Characterization of Si3N4/Si(111) thin films by reflectance difference spectroscopy

“…1(c). According to the literature, 3,7,[9][10][11][12][19][20][21][22] this surface reconstruction can be attributed to the formation of monocrystalline ¢-Si 3 N 4 .…”

“…This transition temperature provides a convenient calibration point of the substrate temperature. 19) On the basis of recent reports, [11][12][13][20][21][22] the optimal substrate temperature for the formation of silicon nitride films was chosen to be µ30 °C below Tt. At this temperature, the bare Si surface was exposed to an active nitrogen flux for 90 s. The plasma conditions were optimized to 350 W RF power and 1.8 sccm N 2 flow rate on the basis of the results of our previous experiments.…”

“…At this temperature, the bare Si surface was exposed to an active nitrogen flux for 90 s. The plasma conditions were optimized to 350 W RF power and 1.8 sccm N 2 flow rate on the basis of the results of our previous experiments. 21,22) The nitrogen cell shutter was closed, and the RF cell was operated in the high-brightness (HB) mode. The 8 © 8 RHEED pattern with the sharp fractional reflections (¹01) and (01) of the Si(111) surface after the nitridation step is shown in Fig.…”