Sequential stages of synthesis of SiC epitaxial films on n- and p-type Si(111) substrates in a mixture of carbon monoxide and silane are studied by X-ray diffraction (XRD) and Raman scattering methods. It was found that the elastic strain in SiC films grown on n-type Si(111) is absent in contrast to SiC films grown on p-type Si(111), where the deformations are formed and completely relaxed by the 40th minute of synthesis. A dramatic change in the SiC film structure is observed on the third minute of the growth, which is associated with the formation and growth of pores in the SiC layer. Differences in the lattice constants of SiC films grown on p- and n-type Si substrates are determined and verified via analysis of the change in the curvature of SiC/Si wafers.

In this work, the influence of porosity of silicon layer with macropores on elastic and thermomechanical properties of SiC/Si substrates synthesized by the atom substitution method has been studied. Calculation of elastic constants of porous silicon has been performed by the finite element method. The results of calculation of the Young’s modulus in [111] direction are in agreement with the estimates obtained by the nanoindentation method of SiC/Si(111) substrates. The proposed theoretical model can be used for determination of elastic properties of SiC/Si substrates of different orientation.