EFFECT OF GROWTH INTERRUPTION ON THE INTERFACE FLATNESS IN METALORGANIC VAPOR-PHASE EPITAXY-GROWN GAAS GAASP HETEROSTRUCTURES/

The interface flatness of metalorganic vapor phase epitaxy-grown GaAs/ GaAsP strained barrier quantum wells has been studied with photolumine scence (PL). The PL peak clearly splits into two peaks when the growth rate is less than 1.7 Angstrom/s or when the growth interruptions are introduced at the heterointerfaces. The energy separation between the two peaks corresponds to the well-width difference by a single monola yer. This indicates that the heterointerfaces are smoothed and that th e islands of large lateral sizes are grown at the heterointerfaces. Th e growth interruption has been carried out either at the top (GaAsP on GaAs) or the bottom (GaAs on GaAsP) interface. It is found that the g rowth interruption is effective for smoothing both heterointerfaces. I n addition, when the growth rate is 3.5 Angstrom/s, the flatness of th e growth front is retained during the growth of 90 Angstrom layer.