CARBON NUCLEATION ON SI(100) USING A NEGATIVE CARBON ION-BEAM

The initial nucleation stages of carbon film on Si(100) substrates wer e investigated by low energy electron diffraction (LEED) and Auger ele ctron Spectroscopy. In the initial stages, energetic carbon ions lead to a phase transformation from a two domain p(2 X 1) to a (1 X 1) LEED structure pattern after about 6 X 10(15) carbon ion/cm(2) dose (3 ato mic layers). At room temperature, the energetic carbon ions are deposi ted as silicon carbide (SiC) up to a thickness of about 10 atomic laye rs. As the deposition temperature increases to 300 degrees C, the thic kness of the SiC interlayer increases to 30 atomic layers. An increase d carbon ion dose leads to the formation of sp(3) or sp(2) rich carbon film depending on the carbon ion energy and the deposition temperatur e. Higher energy (150 eV) C- ion beams and lower deposition temperatur es (room temperature) produce sp(3) rich carbon films. At 150 eV ion e nergy, the transition temperature from sp(3) to sp(2) rich carbon film during deposition is about 150 degrees C. Lower energy (< 50 eV) C- i on beams at room temperature produce sp(2) rich carbon films. During p ostdeposition annealing, the sp(3) rich carbon film deposited at room temperature was converted to an sp(2) rich carbon film above 740 degre es C. (C) 1997 American Vacuum Society.