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© 1998 IOP Publishing Ltd. This work was supported by DGICYT (Project PB93-1256) and by CICYT (Project IN93-0012). The help of Professor A M Baró, Dr A Asenjo and Dr J G´omez-Herrero throughout this work is gratefully acknowledged. G N Panin thanks Spanish MEC for a research grant., A combined scanning electron microscope-scanning tunnelling microscope (SEM-STM) system has been used to characterize CdxHg1-xTe and CdTe crystals, The electron beam induced current (EBIC) mode of the SEM shows the existence of inhomogeneities in the electronic behaviour of the samples, mainly related to the presence of subgrain boundaries and precipitates. Current imaging tunnelling spectroscopy images and the related normalized differential conductance curves, obtained with the STM, reveal the electronic inhomogeneities at a finer scale. In particular, local variations of the band gap were shown by the conductance curves in regions with strong EBIC contrast. SEM-and STM-based techniques in a combined instrument appear to be complementary characterization techniques., DGICYT, CICYT, MEC, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

©1996 - Elsevier Science S.A. All rights reserved. International Workshop on Beam Injection Assessment of Defects in Semiconductors (BIADS 96) (4. 1996. El Escorial, España). N.V.S. and G.P. thank the fellowships from MEC (Spain). This work has been partially supported by CAM [project AE00136/94-TEC) by CICYT (project ESP 95-0148) and by DGICYT (project PB93-1256)., The origin and spatial distribution of radiative defects in undoped and Ge-doped CdTe wafers have been studied by CL spectroscopy and imaging techniques in the scanning electron microscope (SEM) before and after the wafer annealing in HgI2 vapor. The annealing procedure has been carried out under isothermal conditions at 250 degrees C for 24 h for or for 48 h. It has been shown that the annealing results in the growth of alpha-HgI2 polycrystalline layer on the wafer surface, and this layer acts as a getter for Te precipitates distributed randomly over the whole volume of the as-grown CdTe wafers. The annealing affects mainly the CL bands related with Te vacancies (band at about 1.00 eV) and Ge dopant (0.82 and 0.89 eV bands). The contribution of the latter to the total luminescence emission of CdTe wafers decreases after the annealing. The quality improvement of CdTe wafers, revealed by the elimination of Te precipitates from the wafer bulk, has been shown to be an important result of the annealing procedure., CAM, CICYT, DGICYT, MEC, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

(C) 1995 American Institute of Physics. G. Panin thanks Ministerio de Educacion y Ciencia for a research grant and P. S. Dutta thanks CSIR (India) for the award of Senior Research Fellowship. This work was partially supported by the Instituto Nicolas Cabrera, UAM, Madrid, Spain, through a Visiting Scientist Fellowship and by the DGICYT (Project PB93-1256), CICYT (IN93-00129 and ESP95-0148., Inversion in conductivity type of GaSb from p- to n- has been observed as a result of argon ion beam milling. Electron beam induced current (EBIC) measurements have been employed for detecting the type conversion. Enhancement in the luminescence intensity is seen after ion beam treatment. The type conversion is proposed to occur due to a combined effect of generation of native donors and gettering of native accepters originally present in the as-grown samples., DGICYT, CICYT, Ministerio de Educación y Ciencia, Instituto Nicolas Cabrera, UAM, Madrid, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 1996 IOP Publishing Ltd. This work has been supported by DGICYT (project PB93-1256). G Panin thanks the Ministerio de Educacion y Ciencia for a research grant. Japan Energy Corporation is acknowledged for providing some of the samples., The effect of ion milling on the defect structure of CdTe crystals has been investigated in the scanning electron microscope by cathodoluminescence. Enhancement in the luminescence intensity is observed after ion treatment. Luminescence spectra of treated and untreated zones of the samples indicate that ion milling causes generation of tellurium vacancies and filling of cadmium vacancies in a subsurface layer. In addition, enhancement of the concentration of cadmium vacancy related defects in the region extending up to 20 mu m from the layer is revealed. This effect is discussed in connection with models of p- to n-type conversion of CdTe during ion milling., DGICYT, Ministerio de Educacion y Ciencia, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 1998 American Institute of Physics. This work was supported by DGICYT (Project PB93-1256) and by CICYT (Project IN93-0012). The help of Professor A. M. Baro´, Dr. A. Asenjo, and Dr. J. Gómez-Herrero is greatfully acknowledged. G. Panin thanks Spanish MEC for a research grant., A correlative study of the electrically active defects of CdxHg1-xTe and CdTe crystals has been carried out using a scanning electron microscope/scanning tunneling microscope (SEM/STM) combined system. Charged structural and compositional defects were revealed by the remote electron beam induced current (REBIC) mode of the scanning electron microscope. The electronic inhomogeneities of the samples were analyzed with nm resolution by current imaging tunneling spectroscopy (CITS) measurements, which showed the existence of built-in electrostatic barriers as well as local variations of the surface band gap in the defect areas imaged by REBIC., DGICYT, CICYT, MEC, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub