We report spatially resolved Raman scattering from Si-doped epitaxial laterally overgrown GaN structures to investigate spatial variations in stress and free electron concentration. The doping-induced increase in the free electron concentration is relatively higher in the laterally overgrown regions than in the coherently grown regions due to the increased contribution of the high-energy A(1) longitudinal optical phonon-plasmon coupled mode. In addition, the E-2(high) [E-2(low)] phonon energy shifts downward (upward) more significantly in the laterally overgrown regions than in the coherently grown regions. The doping-induced Raman shifts of the E-2(high) and E-2(low) phonons in the laterally overgrown regions are approximately -0.6 and 0.11 cm(-1), respectively, corresponding to the in-plane stress of similar to 0.22 GPa. (C) 2012 Elsevier B.V. All rights reserved.