High-Resolution Electron Microscopy of Semiconductor Heterostructures and Nanostructures

This chapter briefly describes the fundamentals of high-resolution electron microscopy techniques. In particular, the Peak Pairs approach for strain mapping with atomic column resolution, and a quantitative procedure to extract atomic column compositional information from Z-contrast high-resolution images are presented. It also reviews the structural, compositional, and strain results obtained by conventional and advanced transmission electron microscopy methods on a number of III–V semiconductor nanostructures and heterostructures

Elemental composition of reactively sputtered indium nitride thin films.

Indium nitride (InN) thin films have been grown on a variety of substrates using low-temperature radio frequency reactive sputtering of indium metal in pure nitrogen plasma. Quantitative compositional analyses of the films, carried out using X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering spectrometry (RBS), suggest that large amounts of oxygen are present in them. The high concentration of oxygen in our films is attributed to the voided microstructure as revealed by cross-sectional scanning electron microscopy. The XPS studies also suggest that the oxygen incorporated into the films is bonded to nitrogen. © 1996, The Japan Society of Applied Physic

Growth of high purity liquid phase epitaxial GaAs in a silica growth system.

Liquid phase epitaxial gallium arsenide layers, greater than 200 μm thickness and with a low net carrier concentration (NA,D ≈ 1013 cm−3) have been grown in a silicia growth system with silica crucibles. Analysis of electrical and chemical defects was carried out using capacitance-voltage (C---V) measurements, deep level transient spectroscopy (DLTS) and secondary ion mass spectroscopy (SIMS). Details of the growth procedure are given and it is shown that silicon incorporation in the growth layer is not suppressed by the addition of ppm levels of oxygen to the main hydrogen flow. © 1995, Elsevier Ltd

High-resolution X-ray photoelectron spectroscopy of AlxGa1-xSb

Surface oxidation and growth-derived oxygen contamination for Al 0.05Ga0.95Sb films, grown by metalorganic chemical vapour deposition (MOCVD), were systematically investigated using an X-ray photoelectron spectroscopy (XPS) system with high energy resolution. The Sb 3d5/2 and O 1s peaks were well resolved, as were the Ga 3d peaks. All samples investigated show oxide layers (Al2O3, Sb 2O3 and Ga2O5) on their surfaces. In particular, the percentage of aluminium oxide was very high at the sample surface compared to AlSb. Carbon incorporation was also examined. Adventitious surface carbon was high; however, in the bulk material carbon was below the detection limit of XPS and secondary ion mass spectroscopy (SIMS). These results indicate extremely low carbon content for the MOCVD growth of Al 0.05Ga0.95Sb epilayers.5 page(s

Variations in the Apparent Optical Band-gap of RPE-CVD Grown Indium Nitride Thin Films

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Type I and type II alignment of the light hole band in In<inf>0.15</inf>Ga<inf>0.85</inf>As/GaAs and in In<inf>0.15</inf>Ga<inf>0.85</inf>As/Al<inf>0.15</inf>Ga<inf>0.85</inf>As strained quantum wells

We present results of photoluminescence and cathodoluminescence measurements of strained undoped In0.15Ga0.85AsXGaAs and In0.15Ga0.85As/Al0.15Ga0.85As quantum well structures, designed to throw light on the current controversy over light-hole band alignment at low In content. We compare these data with theoretical calculations of the confined state energies within the eight band effective mass approximation. Our analysis shows that for In0.15Ga0 85As/GaAs, the observed two transitions are consistent with either type I or type II alignment of the light hole band for band offset ratios within the accepted range. In the case of In0.15Ga0 85As/Al0.15Ga0 85As, however, our results clearly indicate type II alignment for the light hole band. We derive the band offset ratio Q, defined here as Q = ΔEc/ΔEg where ΔEc is the conduction band offset and ΔEg is the bandgap difference between the quantum well and the barrier in the presence of strain, for the In0.15Ga0.85As/Al0.15Ga0.85As system to be Q = 0.83 and discuss it in the context of the common anion rule

Piezoelectricity in indium nitride

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Nitrogen-rich indium nitride

Elastic recoil detection analysis, using an incident beam of 200 MeV Au ions, has been used to measure indium nitride films grown by radio-frequency sputtering. It is shown that the films have nitrogen-rich stoichiometry. Nitrogen vacancies are therefore unlikely to be responsible for the commonly observed high background carrier concentration. Ultraviolet Raman and secondary ion mass spectroscopy measurements are used to probe the state of the excess nitrogen. The nitrogen on indium anti-site defect is implicated, though other possibilities for the site of the excess nitrogen, such as molecular nitrogen, or di-nitrogen interstitials cannot be excluded. It is further shown that a shift in the (0002) x-ray diffraction peak correlates with the excess nitrogen, but not with the oxygen observed in some samples.5 page(s