It is demonstrated that a complex X-ray characterization of semiconductor films epitaxially grown on metal oxide buffer layers and Si(111) substrates is possible using laboratory-based equipment. This is demonstrated with epi-Germanium on Pr2O3 as buffer material. Pole figure measurements prove that epi-Ge layers grow nearly completely single crystalline with exactly the same in-plane orientati...

The defect structure onattice-mismatched I-pm InxGal_xAs X 10-3) epilayers on GaAs was studied with scanning cathodoluminescence (CL), transmission electron microscopy (TEM), high-voltage electron microscopy, and scanning electron microscopy. CL shows that nonradiative recombination lines exist in the GaAs buffer layer as far as 4000 A from the interface. The density of these defects is indepen...

We have studied the photorefiectance (PR) spectra from a molecular-beam epitaxially (MBE) grown heterostructure consisting of 200 nm of G!lo83 Alo 17 As, a 800-nm GaAs buffer layer on a semi-insulating (81) (100) (LEC) GaAs substrate. By varying both the pump beam wavelength and modulation frequency we are able to identify the component layers, their quality, and the quality of the various inte...

The performance of Z-cut MachZehnder high speed LiNbO, amplitude modulators with a CPW travelling wave electrode, has been analysed and optimally designed in detail by the Fourier series method. The effect of electrode and buffer layer thickness on the electric field distribution in the substract, effective microwave refractive index and characteristic impedance of CPW electrode, are discussed....

Recently, the compound semiconductor Cu(3)BiS(3) has been demonstrated to have a band gap of ~1.4 eV, well suited for photovoltaic energy harvesting. The preparation of polycrystalline thin films was successfully realized and now the junction formation to the n-type window needs to be developed. We present an investigation of the Cu(3)BiS(3) absorber layer and the junction formation with CdS, Z...

AlGaN/GaN high electron mobility transistor (HEMT) structures are grown on 200-mm diameter Si(111) substrates by using three different buffer layer configurations: (a) Thick-GaN/3 × {AlxGa1-xN}/AlN, (b) Thin-GaN/3 × {AlxGa1-xN}/AlN, and (c) Thin-GaN/AlN, so as to have crack-free and low-bow (<50 μm) wafer. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, high resolution-cross...

A combined study of the crystalline structure, the chemical interaction, and diffusion processes of the substrate/layer interface of amorphous-carbon hard coatings is presented. The structure of the coatings and their gradient layer interface to a chromium buffer layer has been investigated on two substrates @Si~100! and tool steel# using x-ray diffraction ~XRD!. Chemical interaction and diffus...

The surface morphology of GaN is observed by atomic force microscopy for growth on GaN and AlN buffer layers and as a function of III/V flux ratio. Films are grown on sapphire substrates by molecular beam epitaxy using a radio frequency nitrogen plasma source. Growth using GaN buffer layers leads to N-polar films, with surfaces strongly dependent on the flux conditions used. Flat surfaces can b...

For the perpendicular-magnetic-tunneling-junction (p-MTJ) spin valve with a nanoscale-thick bottom Co2Fe6B2 free layer ex situ annealed at 400 °C, which has been used as a common p-MTJ structure, the Pt atoms of the Pt buffer layer diffused into the MgO tunneling barrier. This transformed the MgO tunneling barrier from a body-centered cubic (b.c.c) crystallized layer into a mixture of b.c.c, fa...