The nucleation and growth of In on a vicinal Si(100)-(2×1) surface at high temperatures by femtosecond pulsed laser deposition was investigated by in situ reflection high energy electron diffraction. Intensity relaxation was observed for the first ~2ML during the growth of In(4×3) by step flow. From the temperature dependence of the rate of relaxation, an activation energy of 1.4eV for surface diffusion was determined. The results indicated that small In clusters diffused to terrace step edges with a frequency factor of 1.0 x 1011/s. The RHEED specular beam split peak spacing, which was characteristic of a vicinal surface, was analyzed with respect to growth temperature to obtain the average terrace width. Gradual reduction in the terrace width during growth of In(4×3) was observed with In coverage and was attributed to the detachment of In atoms from terrace edges. At a substrate temperature of 405C, the average terrace width decreased from 61Å, which corresponded to the vicinal Si(100) surface, to an equilibrium value of 45Å after deposition of ~23ML. Further In coverage showed a transition of the RHEED pattern from (4×3) to (1×1) and the growth of rounded In islands (average height of ~1nm and width of ~25nm), as examined by ex situ atomic force microscopy.

Activation Energy of Surface Diffusion and Terrace Width Dynamics during the Growth of In(4x3) on Si(100)-(2x1) by Femtosecond Pulsed Laser Deposition. M.A.Hafez, H.E.Elsayed-Ali: Journal of Applied Physics, 2008, 103[9], 093510

Figure 3

Diffusion of Na in Si

(Open circles: O-containing Si; filled circles: float-zone Si)