Iron is one of the most important impurities in silicon integrated-circuit technology. We present a fast (5 min), essentially preparation-free large-area (25 cm2 ) technique to determine the Fe concentration in boron-doped silicon with a sensitivity of 2–5×1011 cm−3. The principle of the method is based on the fact that interstitially dissolved Fe undergoes a reversible pairing reaction with boron and that the minority-carrier diffusion length—as measured by the surface photovoltage method—is modified by this reaction. The method has been calibrated by deep-level transient spectroscopy and is also suitable to measure a surface Fe contamination in combination with a rapid thermal annealing diffusion step.

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SiO, layers that are applied in VLSI (very large scale integration) microelectronics (gate dielectric, insulation, etc) are prepared in different ways: thermal, chemical vapour deposition (CVD), thermochemical.It has been investigated whether the composition, thickness, film stress and disorder of thin silicon dioxide can be characterised in a simple manner by Fourier-transform infrared absorption spectroscopy (FT-IR). In addition to the main absorption bands at 460 cm", 808cm" and 1075 cm" (all transverse optical modes) spectral features at 1165 cm", 1200 cm" ( L O ~-T O ~ pair) and 123C-1250 cm" LO^ mode) have been analysed as a function of film thickness, preparation condition, substrate and rapid thermal annealing. The position, full width at half maximum of the band at 1075 cm -l , the position of the LO^ mode and the intensity ratio of the L O ~-T O ~ pair and the LO^ mode can be related in a qualitative fashion to film stress, composition and disorder of the thin SiO, films.