SELF-ASSEMBLED INP ISLANDS GROWN ON GAP SUBSTRATE

InP islands are grown on a GaP substrate by organometallic vapor-phase epitaxy using tertiarybutylphosphine and characterized by atomic forc e microscopy and transmission electron microscopy. InP grows two-dimen sionally at first and then begins to grow three-dimensionally at 1.2 M L. The island sizes are 400 nm in lateral dimension and 100 nm in heig ht at 1.8 ML with the growth temperature of 550 degrees C. The island density increases with increasing InP layer thickness while the island size remains the same. Misfit dislocations are observed in the island s at 1.8 ML growth. By lowering growth temperature to 420 degrees C, t he island size becomes as small as 40 nm in the lateral direction, mor eover smaller islands without dislocations are obtained. The formation mechanism of large islands is discussed. (C) 1998 Elsevier Science B. V. All rights reserved.