STRAIN EFFECT ON THE GROWTH OF 3D IN(GA)AS WIRE STRUCTURES ON INP(001)

The 2D-to-3D transition process of strained In(Ga)As layers epitaxied on InP(001) was studied by scanning tunneling microscopy at compressiv e mismatches of 2 and 3.2%. During growth, the surface morphology exhi bits characteristic evolutions. First, multisteps are formed at 2D pla telet edges, then a transition with noticeable matter transport arises , giving 3D wire-like structures. The transition occurs between four a nd five deposited monolayers at 2% mismatch and between two and three monolayers at 3.2% mismatch. Matter redistribution from highly stresse d lower terraces to the relaxed top edges of platelets appears to be a n energetically favorable process which can explain the formation of 3 D wire-like structures. (C) 1998 Elsevier Science B.V. All rights rese rved.