Real-time observation of ellipsometry oscillation during GaAs layer by layer growth by metalorganic vapor-phase epitaxy

Ellipsometry oscillations during GaAs metalorganic vapor-phase epitaxy on G aAs (001) substrates were observed. The ellipsometric signal was found to o scillate at a period corresponding to 1 monolayer of GaAs growth. Excellent agreement was seen between growth rate data from oscillation period and th ose from thickness measurements after growth (deviation: <1%). Oscillation clearly depends on growth temperature and source gas material. The results suggest that ellipsometry oscillation originates from the absorption of pro be light by Ga-alkyl bonds at the edges of 2-dimensional islands.