110 keV nitrogen ions (N+) of fluences 1×10 14-1×1017 cm-2 have been implanted in liquid encapsulated Czochralski grown Fe-doped semi-insulating indium phosphide (InP) single crystal substrates. Grazing incidence X-ray diffraction measurements on as-grown and implanted samples have been carried out and analyzed. At all above fluences, a broad hump in the region of InP(1 1 1) peaks is observed. It might have resulted from implantation-induced misoriented grains along certain preferred orientations. The peak observed at a d-value of 1.77 Å for all the fluences becomes more pronounced as the implantation fluence increases up to 1×1016 cm-2. This could indicate formation of an Indium phosphide nitride alloy. Post-implantation annealing reduces the structural defects and assists in the growth of the nitride phase. © 2003 Elsevier B.V. All rights reserved.