[en] Electroreflectance spectra of polycrystalline ZnS:Mn thin films grown by atomic layer epitaxy and electron beam evaporation techniques for electroluminescent devices are measured in the photon energy range from 3.0 eV to 4.5 eV. From the E₀ direct electron transition peaks observed at 3.74 eV and 3.71 eV it is concluded that the crystal structure of the ZnS thin films grown by atomic layer epitaxy is almost hexagonal 2 H where as that of the films grown by electron beam evaporation is close to polytype 4 H or 6 H

No abstract available

[en] This special issue dedicated to Professor Erkki Laurila, the pioneer of technical physics in Finland, consists scientific works writen by his students, collegues and others working in the field of technical physics. Technical physics is here considered in its broadest sense, including in addition to physics and the technical sciences also mathematics, information science and economics. This special issue contains 26 papers from applied physics, applied mathematics, material science, nuclear and energy technology, science, geophysics, metallurgy, control science, instrumentation and electronics

[en] The electronic transitions E₀, E₀ + Δ₀, E₁, and E₁ + Δ₁ of In/sub 1-x/Ga/sub x/As/sub y/P/sub 1-y/ lattice matched to InP are studied by means of the electroreflectance method (ER). The samples grown using liquid phase epitaxy cover the range from y = 0 to 0.642. The three-point method developed by Aspnes and Rowe is commonly used for the accurate determination of the critical point parameters from the ER spectra. In this study an extension of the three-point method is suggested for the line profile analysis of the overlapping structures in the ER spectra originating at two adjacent critical points. (author)

[en] Large area transmission and section topographs of semi-insulating gallium arsenide wafers grown by the gradient freeze technique are made with synchrotron radiation at HASYLAB in Hamburg and at ESRF in Grenoble. Several high-resolution images including stereo pairs are obtained on the same film at a time. A typical dislocation line is an arc of a circle which starts from one surface and ends at the same surface. From the disappearance of the dislocation image and using the g · b = 0 criterion it is concluded that the Burgers vector b of the most common dislocations is parallel to <110>. Rather large volumes of the wafer are dislocation-free. Section topographs of epitaxial wafers show defects and strain fields at the interface between an n-type substrate and the epitaxial layers grown by chemical vapor deposition. The results are compared with those obtained from detector performance measurements

[en] A versatile PIXE chamber with several positions for detectors and a four-stage collimator set-up has been constructed. A remote control operation of sample changing is carried out by means of a stepping motor mechanism and a logical circuitry for correct sample positioning and adressing. The transfer of a ladder assembly, which enables entry of 20 samples simultaneously into the chamber vacuum, is controlled optically. Analyses of air particulate matter and biomaterial using the PIXE facility are discussed. (orig.)

[en] Synchrotron section topographs showing a set of parallel Pendelloesung fringes typical of a perfect silicon wafer are measured with a direct X-ray sensitive linear charge-coupled device (CCD) at room temperature. The results are compared with those calculated from the dynamical theory of X-ray diffraction and with those measured from a highest resolution X-ray film with a densitometer. No radiation damage is observed in the experiment. (orig.)

No abstract available

[en] Section topographs made with synchrotron radiation show the strain field below the surface of silicon wafers which have gone through a process for integrated circuits. The contrast observed is a series of curved lines starting at one edge of an oxide layer and ending at its other edge. The strain is also calculated using the finite-element method. Electrical measurements such as the threshold voltage of a transistor are made in order to find the influence of the strain on the device performance and yield

[en] A linear charge-coupled device (CCD) having a picture element size of 7 μm is employed for direct measurement of synchrotron x-ray topographs. Deterioration of the detector is not observed. The intensity distribution of a section topograph of a perfect silicon crystal is measured by both the CCD camera and a high-resolution x-ray film and the results are compared to the theoretical Pendelloesung fringe pattern