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Effect of disorder on structures due to interband transitions in silicon
No full textThe optical response of silicon near the E1 structure, due to interband transitions, has been studied as a function of disorder by means of electroreflectance (ER). It is found that crystal grains smaller than the Rutherford backscattering (RBS) spatial resolution can still give rise to a measurable signal. The ER lineshape is briefly discussed and some important features are stressed
Investigation of doping in Si crystals by means of electroreflectance
No full textIn this work the importance of electroreflectance is evidenced in two specific applications concerning studies of semiconductor surfaces: i) determination of junction depths and carrier profiles, ii) mapping of inhomogeneity curves of the carrier distribution on Si surfaces. New information in both cases is obtained and briefly discussed
Infrared angular spectroscopy characterization of epitaxial layers of n-type silicon grown on N+ or P+ substrates
No full textIn this paper the technique of infrared angular spectroscopy applied to the characterization of epitaxial layers of n-type silicon grown on N+ or P+ substrates is illustrated. Some results are reported and discussed concerning films having a free-carrier concentration ranging from 1014 cm−3 to 1017 cm−3 and thickness of the order of 10 μm. A significant comparison with results obtained by other techniques (four-point probe, spreading resistance, C−V plots, etc.) is performed and a few simple conclusions are drawn
Optical Interference to Determine the Free Carrier Concentration in Semiconducting Epitaxial Layers
No full textIn this paper, it is shown that the analysis of the interference fringes due to light reflected from an N-type siliconepitaxial layer grown on an N+ silicon substrate can give both thickness and free carrier concentration of the film, provideda few requirements are met. The technique, which is typically nondestructive, is characterized by a sensitivitywhich is better than in other optical methods
Il problema dell'adattamento delle proprietà ottiche dei materiali a particolari esigenze applicative
No full textInfrared thermoreflectance of VχTi(1-χ)Se2
No full textThermoreflectance data in VχTi1-χSe2 show that an interband optical structure, present both below and above the transition temperature, is relatively unaffected by the vanadium content (for χ <= 1.5%)
Optical determination of free-carrier concentration in epitaxial layers of n-type silicon grown on N+ or N− substrates
No full textIn this paper it is shown that the optical determination of free‐carrier concentration N0 in 5–10 μm thick epitaxial layers of n‐type silicon grown on N+ or N− substrates is possible for concentrations ≥2×1016 cm−3 by measuring p‐polarized reflected light Rp near the Brewster angle at a wavelength ≂10 μm. Good crystallinity, constant concentration profiles normal to the surface, as well as relatively small differences in the index of refraction with respect to the substrate are essential requirements in order to get high resolution. Good agreement with the angular derivative of Rp is obtaine
New achievements of electroreflectance to study doping inhomogeneities in semiconductors
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