The formation of 3C-SiC in crystalline Si by carbon implantation at 950 degrees C and annealing - a structural study

3C-SiC(cubic) was formed by carbon implantation into (001) and (111)Si with doses ranging between 0.2 x 10(18) and 1 x 10(18)cm(-2) at 200 keV. During implantation the samples were maintained at a temperature approximate to 950 degrees C and they were subsequently annealed at 1250 degrees C for 6 h. In all samples a buried 3C-SiC layer was formed, which consists of a high density of 3C-SiC precipitates having the same orientation as the Si matrix. The coherency of the SiC precipitates with the Si matrix is shown for the first time by high resolution transmission electron microscopy (HRTEM) observations. The 22% misfit between the two lattices is accommodated by misfit dislocations, which form loops around the precipitates. From the shift of the displacement type moire patterns which were formed by superposition of the mismatched 3C-SiC and Si lattices the portion of the misfit accommodated by partial dislocations was deduced. The stability of the SiC precipitates during the high temperature anneal is shown. A mechanism for the formation of the 3C-SiC, without the generation of defects in the Si matrix, is proposed. Low dose high temperature carbon implantation through a SiO2 capping layer into the near surface region of the underlying silicon results in the preferential nucleation and growth of 3C-SiC on the silicon side of the SiO2/Si interface, the advantages of such structures are discussed.