Cubic boron nitride (cBN) is a superhard material, which is defined as a material with microhardness over 40 GPa, and offers the best combination of high hardness, low friction coefficient, resistance to oxidation, and resistance to chemical degradation with iron-based materials. Other applications of cBN take advantage of its high density, high thermal conductivity, good transparency in the visible and infrared portion of the spectrum, and high electrical resistivity. Cubic BN is also a wide band gap semiconductor, which can be n- and p-type doped. Several models have been proposed to describe the nucleation and growth of cBN thin films based on the observation of the necessity of energetic bombardment of the growing film for the stabilization of the cubic phase. These models include the concept of thermal spikes, the subplantation model, stress-induced stabilization, and resputtering of the BN hexagonal phase. Several authors have been able to correlate the energetic bombardment with P/a, the total momentum imparted to the growing film per arriving boron atom. In this report, the use of a high intensity, low energy ion source, incorporated to an ion beam assisted deposition system to study the kinetics of the cBN thin film nucleation at bombarding ion energies in the 50-100 eV range will be discussed. It will be shown that the control of the ion bombardment and of the incoming boron atom flux is critical for the kinetics of formation of the boron nitride films. The implications for the nucleation process of the BN cubic phase and a comparison with systems using high deposition rates will be discussed.