In the present work a fabrication process based on a controlled semi-isotropic reactive plasma etching of single crystal silicon has been formulated to create sharp Si-tips of desired heights using high-resolution electron beam lithography for the realisation of high-density field emission arrays. PMMA was used as e-beam resist and patterns in the shape of squares were transferred to a 2000 Å thick thermal oxide, which was used as etch mask for the subsequent reactive plasma process. For the development of desired RIE process for the etching of silicon tips, a number of Fluorine based plasma processes have been analysed to control the various parameters in order to achieve a desired shape of the sidewalls. Different kinds of wall profiles have been generated to obtain ultimate sharp-silicon tips. Two approaches have been followed, one, a multi-step and another, single step reactive plasma process. Silicon tips with a density of 6.25 × 106 tips/cm2 have been fabricated. Salient features and limitations of the fabrication process are discussed.