Heteroepitaxial growth of 3C-SiC on Silicon-Porous Silicon-Silicon (SPS) substrates

This paper presents a new compliance substrate for heteroepitaxial growth of β-SiC on silicon able to partially relax the huge stress caused by both the lattice mismatch and the thermal expansion coefficient difference. We present substrate treatments to achieve the required SPS substrates. The porous region is characterized from a double porosity in order to make easier pores locking up on the surface through the growth of an ultra-thin silicon layer on it by using both APCVD reactor or UHV system (as SSMBE). On such substrates a preliminary study of SiC growth is performed and compared with SiC growth on Si(100) flat substrate. 3C-SiC growth is performed in an horizontal hot-wall CVD reactor by using hydrogen, sylane and ethylene gasses in a low-pressure regime. Moreover, this approach is very interesting in realization of free-standing 3C-SiC wafers disconnected from Si substrates and for thermal stress relief on the substrate only.