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 k eV. During implantation the samples were maintained at a temperature a pproximate to 950 degrees C and they were subsequently annealed at 125 0 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 sam e orientation as the Si matrix. The coherency of the SiC precipitates with the Si matrix is shown for the first time by high resolution tran smission electron microscopy (HRTEM) observations. The 22% misfit betw een the two lattices is accommodated by misfit dislocations, which for m loops around the precipitates. From the shift of the displacement ty pe moire patterns which were formed by superposition of the mismatched 3C-SiC and Si lattices the portion of the misfit accommodated by part ial dislocations was deduced. The stability of the SiC precipitates du ring the high temperature anneal is shown. A mechanism for the formati on of the 3C-SiC, without the generation of defects in the Si matrix, is proposed. Low dose high temperature carbon implantation through a S iO2 capping layer into the near surface region of the underlying silic on results in the preferential nucleation and growth of 3C-SiC on the silicon side of the SiO2/Si interface, the advantages of such structur es are discussed.