INTRINSIC STRESS UPON STRANSKI-KRASTANOV GROWTH OF GE ON SI(001)

It is well established that the growth of Ge on SL(001) proceeds by St ranski-Krastanov mode, i.e. 3D islands (''hut'' and macroscopic cluste rs) nucleate on top of a 3-4 ML thick pseudomorphic layer. Here, we pr esent in-situ intrinsic stress measurements of Ge/Si(001) up to the fi lm thicknesses at which the 3D islands percolate. From the film stress - and supported by AFM investigations - three stages of film growth c haracterised by different reliefs of the misfit strain can be discrimi nated: (1) the pseudomorphic layer-by-layer stage, (2) nucleation and growth and (3) coalescence of 3D islands. (C) 1998 Elsevier Science B. V. All rights reserved.