Residual stress study of silicon quantum dot in silicon carbide matrix by Raman measurement

Two different annealing processes have been applied on Silicon rich SiC_X amorphous samples: furnace annealing at 1100 °C/1hr and RTA at 1100 °C/30 sec. After annealing, both Si and SiC nanocrystals were clearly observed from TEM image and evaluated from XRD results. Peak position of Raman results are more blue shifted from Si reference wafer position in RTA samples (Δ=5.4 cm^‐1) compare with furnace annealing samples (Δ=2 cm^‐1), indicating greater tensile stress is applied on Si nanocrystals. This is because of different thermal expansion coefficient of Si and SiC crystals and fast temperature ramping rate in RTA process. In order to release the stress in RTA samples, additional annealing process has been applied. Raman analysis indicates, after applying an additional furnace annealing, all samples with different Si concentration could release most of the residual stress. But residual stress in low Si concentration samples could not be as well released by additional RTA due to insufficient time duration.