Crystal growth processes of multicrystalline silicon and their potential for further development are reviewed. Important parameters for the assessment of the final efficiency of the solar cells and the production yield are the bulk lifetime and the mechanical stability. The distribution and morphology of lattice defects can be related to the electrical properties, In particular oxygen in multicrystalline ingots and carbon in EFG ribbons and their interaction with extended defects such as dislocations and grain boundaries will be discussed. The fracture strength depends on microcracks that are introduced through wafer slicing. The current understanding will be reviewed here. (C) 2005 Elsevier B.V. All rights reserved.