It was recalled that Ci and CiCs were the 2 main defects produced via the Watkins replacement mechanism when Si-based materials containing C were subjected to particle bombardment. Previous experimental observations on these defects in relaxed Si1-xGex alloy layers were re-examined here in the light of very recent and thorough theoretical investigations. Two main issues were considered here. Firstly, the role of alloying upon the position of the electrical levels in the band-gap was considered: a linear shift towards the valence band with the same rate of all related levels was observed experimentally and predicted theoretically. Secondly, the dynamics of migration of interstitial C (Ci) in the process of forming CiCs was analyzed. The suggestion that Ci migrated via Si-based paths was thus found to have some theoretical justification.

Interstitial-Carbon-Related Defects in Relaxed SiGe Alloy - the Effect of Alloying. A.Mesli, A.Nylandsted Larsen: Journal of Physics - Condensed Matter, 2005, 17[22], S2171-84