The incorporation of high concentrations (≳1019cm−3) of Si, Be, and C in InxGa1−xAs relaxed layers has been studied as a function of In content (x≤0.16) by Raman spectroscopy of local vibrational modes (LVM). The frequencies of the Raman peaks resulting from the convolution of several split modes shift to lower values as the In content is increased, the carbon acceptor (CAs) local mode frequency showing the strongest dependency onx. Features attributed exclusively to the influence of In on second‐neighbor sites are identified only in the Si‐doped samples. The transverse and longitudinal modes expected from the splitting of a LVM of CAswith one In first neighbor are not observed in layers withxup to 0.085. A new calibration for the BeGa, CAs, and Si‐related LVM leads to the conclusion that In increases the total electrical activation of Si and favors its incorporation on group‐III sublattice sites. In contrast, no influence of In on the Be or C doping activation has been detected. The analysis of the CAsLVM spectra supports the view that in InxGa1−xAs CAsis preferably surrounded by Ga instead of In atoms forx≤0.085. ©1995 American Institute of Physics.