Morphological features and nanostructures generated during SiC graphitization process

Surface morphological features and nanostructures generated during SiC graphitization process can significantly affect fabrication of high-quality epitaxial graphene on semiconductor substrates.In this work,we investigate the surface morphologies and atomic structures during graphitization process of 4H-SiC(0001) using scanning tunneling microscopy.Our high-magnified scanning-tunneling-microscope images exhibit the appearance and gradual developments of SiC(1 × 1)nanostructures after 1100℃ cleaning treatments,irregularly distributed among carbon nanocaps and(√3×√3) reconstruction domains.A model for the formation and growth progression of SiC(1 × 1) nanostructures has been proposed.When post-annealing temperature reaches 1300 ℃,the nanoholes and nanoislands can be observed on the surface,and multilayer graphene is often detected lying on the top surface of those nanoislands.These results provide profound insights into the complex evolution process of surface morphology during SiC thermal decomposition and will shed light on fabrication of SiC nanostructures and graphene nanoflakes.