Indium antimonide (InSb) is known to have the smallest band gap energy amongst the III-V semiconductor alloys. Incorporation of dilute nitrogen into this alloy lowers its bandgap further, making it a suitable material for infrared imaging and outer space applications in 8-12 µm wavelength range. Further, Auger suppression in InSbN makes it a better material than the existing HgCdTe based systems for device applications. However, incorporation of nitrogen leads to defects, due to its smaller atomic size. In this work we present a comprehensive study of growth and characterization of InSbN layers grown on semi-insulating GaAs (001) substrate by solid source molecular beam epitaxy. A systematic study on the crystalline, optical, morphological and vibrational properties correlating the growth conditions and effect of N incorporation has been carried out. InSbN epilayers of thickness ~0.8 µm were grown on 1.5 µm thick InSb buffer layer at three different substrate temperatures 290 °C, 330 °C and 380 °C. Additionally, 2 µm thick InSbN epilayers were grown at 330 °C and 380 °C for transmission and reflection measurements. High resolution x-ray diffraction (HRXRD) (004) scan of these nitride samples exhibit a tensile strained epilayer peak with the lowest full width at half maxima of 198 arc-sec, except for the sample grown at 380 °C where no distinct peak corresponding to InSbN is observed. The N composition in these samples are estimated to be around 1.4% based on the x-ray simulation data on similar InSbN samples grown on InSb substrates. The nitrogen incorporation in all the above samples was also evident from the observation of N 1s peak in the corresponding x-ray photoelectron spectra (XPS). The sample grown at 380 °C demonstrates the highest percentage of In-N-Sb bonding, responsible for the band gap reduction in InSbN material system. However majority of the nitrogen was found to be in the form of In-N bonding. Absence of interstitial N-N in XPS is expected to lead to lower carrier concentration for improved device performance. Micro-Raman spectroscopy performed on all the above as-grown epilayers exhibit only longitudinal optical (LO) and transverse optical (TO) modes, indicating absence of Sb antisite and nitride related defects. InSbN sample grown at 380 °C exhibits the least TO/LO intensity ratio, indicating the best quality of the crystal structure. Atomic force microscopy studies showed a relatively smooth surface of root mean square roughness in the order of 5 nm for the nitride sample grown at 380 °C as compared to all other samples. Absorption edge for these samples occurred in the wavelength region of 6- 6.2 µm. Variation of this absorption edge with N concentration will also be presented. This work is supported by the Army Research Office (Grant No. W911NF-10-1-0316, technical monitor Michael Gerhold).