Triangular nano-scale pits (TNPs) of Si3N4 are fabricated by reactive nitrogen ion sputtering using low energy nitrogen ions on the Si (553) surface at 500 °C. The electronic structure of the developing Si3N4 interface was monitored in-situ by Auger Electron Spectroscopy (AES) while the ion beam induced surface reaction was analysed via X-Ray and Ultraviolet photoemission spectroscopy (XPS & UPS), Photoluminescence and Raman spectroscopy. The morphological development of nanoscale pit structures was observed by Scanning Electron Microscopy (SEM). The formation of Si3N4 was identified by AES, with the appearance of the characteristic reacted Si(LVV) peak at 83 eV, while photoemission spectroscopy confirmed the stoichiometry of Si3N4. The valence band maximum was observed to be located at 2.4 eV below the Fermi level. SEM images showed uniformly distributed Si3N4 TNPs with size varying between 250 to 600 nm (length) and 200 to 400 nm (width). Our work underlines the influence of ion energy and substrate temperature and establishes the conditions for the growth of Si3N3 TNPs by ion induced reactive sputtering.