https://doi.org/10.1140/epjst/e2008-00397-4
Photothermal measurements in determination of the thermal diffusivity of SiC*
1
Silesian University of Technology, Institute of Physics, Krzywoustego 2, 44-100 Gliwice, Poland
2
Institute of Electron Technology, Lotników 32/46, 02-668 Warszawa, Poland
In this work a measuring method for determination of the
thermal diffusivity of SiC substrates commonly used in electronic industry
is proposed. Such substrates are (300 
900) μm thick plates, The
method bases on generation of temperature field disturbance in the sample by
modulated light beam. Fitting of theoretical curves to the ratio of signals
measured in two experimental geometries as a function of modulation
frequency allows determination of the thermal diffusivity and optical
absorption of the sample. Optical absorption is also measured independently
using typical spectrometer. Results obtained for a few SiC substrates
confirm usability of proposed method for investigation of such samples.
Determined thermal diffusivities of polycrystalline samples are of the order
of (0.2 0.5) cm2 s - 1. The thermal diffusivities of single
crystals are considerably higher and reach (1.3 1.5) cm2 s-1.
© EDP Sciences, Springer-Verlag, 2008
