IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Nanometer Structures Thursday Sessions
       Session NS-ThP

Paper NS-ThP16
STM Observation of Nanoscale Defects Formed by Annealing the 6H-SiC Surface

Thursday, November 1, 2001, 5:30 pm, Room 134/135

Session: Poster Session
Presenter: M. Yoshimura, Toyota Technological Institute, Japan
Authors: M. Yoshimura, Toyota Technological Institute, Japan
K. Ojima, Toyota Technological Institute, Japan
K. Ueda, Toyota Technological Institute, Japan
Correspondent: Click to Email
It was recently reported that the carbon nanotube can be produced on the SiC surface by annealing at high temperature around 1800K. Carbon-terminated surface is considered to be more appropriate for the growth of nanotube than the Si-terminated surface. The transimission electron microscopy (TEM) has been utilized to investigate the growth mechanism for both surfaces. However the determination of the precise atomic structure, such as the location of the pentagons and defects, is difficult only by TEM observation. Here we demonstrate scanning tunneling microscopy (STM) study of the elucidation of Si-terminated SiC surface by annealing. A commercially available 6H-SiC wafer (CREE) was used as a specimen. It was annealed up to 2000K in UHV. STM observation was performed at room temperature with a tungsten tip. After annealing at 1600K, following defect structures were observed on the flat graphite layer; (1)Protruded particles with 4-5nm in diameter were observed and its surface showed /3x/3 superstructure. (2) Nanotube-like structures lie on the surface. They are probably formed by rolling of a graphite layer from the step. (3) Star-shaped defects of 3nm size were frequently observed. The surrounding graphite area also shows the /3x/3 superstructure. The surface was then annealed to 2000K, however, the surface structure was basically unchanged and no nanotube formation normal to the surface was detected. We discuss detailed structure of the defects and its formation mechanism.