Raman scattering by localized vibrational modes and plasmons has been used to characterize heavilyp‐ andn‐type silicon‐doped (311)AGaAs layers grown by molecular beam epitaxy. Consistent with the doping character,p‐type samples show two modes associated with Si(As) and the complex defect Si‐X. Acceptor‐related lines were not observed inn‐type samples, an indication that compensation levels in the layers are very low. The results are discussed in relation to growth conditions on (311)Asurfaces.