InN epi-films were grown on nitrided silicon nitride (Si3N4) layer/Si(111) substrate by radio-frequency plasma-assisted metal-organic molecular beam epitaxy (RF-MOMBE). We have investigated the effect of nitrided Si3N4 layer on the structural, optical and electrical properties of the InN films with different nitridation time. The thickness of the single crystalline β-Si3N4 layer was confirmed with index of refraction by Ellipsometer. When the nitridation time at 60 min, the Si3N4 layer was nearly to stoichiometry. Also, thickness of Si3N4 was measured around 7.23 nm. The X-ray diffraction (XRD) pattern shows a wurtzite InN structure with oriented (0001). Phi-scan XD shows the InN films grew epitaxially on the Si(111) substrates. The mobility of InN layer was determined by Hall effect analyzer and found to be in the range of 16.8-64.1 cm2/V-s.