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Noncontact, nonintrusive photocarrier (PCR) and photothermal radiometry (PTR) as well as Raman spectroscopy were used to characterize GaSb and Te-doped GaSb wafers used to grow GaSb-based heterostructures for infrared applications. The results indicated excellent sensitivity of PTR and PCR to the Te distribution on the wafer surface. The results from the three methodologies were consistent and indicated that the Te was segregated toward the edge of the GaSb wafer. The PTR and PCR laser-based techniques show great potential advantages to characterize the homogeneity of the Te doping in the GaSb wafers and for other steps in the fabrication of semiconductor heterostructures.

This paper shows the in‐situ study of the wetting process in Silicon during anodization process using an electrochemical Differential photoacoustic Cell (DPC). The Photoacoustic amplitude and phase signals were obtained for samples in air, ethanol, ethanol/HF and finally air. According to these results ethanol is responsible for a mechanical contact reducing the superficial tension and ethanol/HF produce the removing of the SiOx and SiO2species on the Silicon surface. It was found that the DPC is a powerful technique to study the wet surface before the formation of the porous silicon layer (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

In order to study in situ the growing process of porous materials, a new electrochemical differential photoacoustic cell (DPC) was developed. This system allows to obtain the thermal signals coming from the growing process of the pores without the external noise component. The DPC is a good system to growth porous silicon and study their growing process with reproducibility. The porous silicon samples were obtained by using electrochemical etching of (100) n-type silicon wafers with different nominal resistivity values in the range of 1-25 Omega cm. The samples were formed in a solution of hydrofluoric acid and ethanol having a composition ratio of 1:1 in volume with etching voltage of 10 V and an etching time of 2 min using back illumination provided by a laser beam with a wavelength of 808 nm. The porous samples were characterized by means of Raman microscopy, x-ray diffraction, and scanning electron microscopy. The crystallite sizes of the samples were obtained through the analysis of the micro-Raman spectra using a phonon confinement model, and the analysis of the x-ray diffractograms.

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