The fluxes of ions and neutral sputtered particles incident at the growth surface during the deposition of TiN by reactive magnetron sputtering from a Ti target in mixed Ar+N2discharges were determined using a combination ofinsitudouble‐modulation mass spectrometry, Langmuir probe, discharge, deposition rate, and film composition measurements. The N2fractionfN2in the discharge was varied from 0 to 1 with the total pressure maintained at 3 mTorr (0.4 Pa). Target nitridation, observed directly through the detection of sputter‐ejected TiN molecules, was found to occur over the narrowfN2range between ≂0.035 and 0.06. WithfN2<0.1, more than 94% of the ion flux incident at the substrate is Ar+while for pure N2discharges, N+2accounts for more than 95% of the incident ions. Both the incident Ar+and N+2ion fluxes are highly monoenergetic with energies corresponding toeVs, whereVsis the applied negative substrate bias with respect to the plasma potential. However, the energy distributions of incident Ti+and N+ions are extended due to the high‐energy tails in their sputter‐ejection energy distributions. The primary sputter‐ejected particles are Ti and N atoms. TiN, TiN+, and Ti+do not contribute significantly to film growth kinetics.