Molecular beam epitaxial growth of III-V semiconductor ... - KOBRA

7.5 Optimization of MEE Followed by MBE Growth of GaP Buer on Si Substrate
7.4.2 MEE - P 2 /Ga Ratio
Another two samples treated as described in Sec. 7.3 were loaded into the MBE
growth chamber and have been grown with the same growth conditions described
in Sec. 7.4.1 at a growth temperature of 350 ◦ C. In this study, the V/III ratio
of Ga and P 2 was varied from 5 to 15. AFM surface prole images (Fig. 7.3) of
the grown samples shows that sample exposed by more P 2 (∼ 15x Ga ux) has
a lower RMS value of 0.46 nm.
Figure 7.3:
(1 × 1 µm 2 ) AFM images of 10 nm GaP/Si with dierent V/III ratios
using Ga-initiated MEE-mode growth. (a) 15, RMS of 0.46 nm, (b) 5, RMS of 0.82 nm.
The MEE growth parameters with 10 nm thickness, P 2 /Ga ratio of 15, Ga
growth rate of 100 nm/h, Ga-initiated growth 10 s Ga/ 4 s stop/10 s P 2 /60 s
and growth temperature of 350 ◦ C were used in all next MEE growth recipes as
optimized parameters.
7.5 Optimization of MEE Followed by MBE Growth
of GaP Buer on Si Substrate
The GaP/GaP homoepitaxy work provided a background for the GaP/Si MBE
growth parameters selection. The GaP-MEE/Si was anticipated to be a suitable
surface as a virtual GaP substrate for additional GaP-MBE growth. The standard
growth temperature of GaP/GaP homoepitaxy is around 550 ◦ C [136]. To optimize
this growth regime, two parameters, P 2 /Ga ratio and growth temperature
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