A novel oxygen stuffing method for the collimated titanium nitride (TiN) diffusion barrier layers by using rapid thermal oxidation (RTO) process was studied. Rto process showed a clearly inproved oxygen stuffing and diffusion barrier property for the collimated TiN compared to conventional furnace annealing process. Aluminum planarization was performed with TiN barrier layers(conventional and collimated)onto various sizes of sbu-half micron contacts to examine electrical properties of the barrier layers. When the conventional furnace annelaing method was used for the barrier layers, $1200{AA}$ conventional TiN showed junction spikings below at $0.45{ imes}0.54;{mu}m$ contact size. Due to the improved bottom coverage, furnace-annelaed collimated TiN showed no junction leakage failure above at $~1000{AA}$. By using RTO process, collimated TiN showed sound electrical contact properties with no junction leakage failure at $~600{AA}$ thickness for the $0.36{ imes}0.45;{mu}m$ contacts.