Growth and Properties of LPCVD Titanium Nitride as a Diffusion Barrier for Silicon Device Technology

Chemical vapor deposition has been used to deposit titanium nitride ( TiN ) on silicon wafers at low pressures in a cold‐wall single‐wafer reactor. Experiments are reported for pressures in the range of 100–300 mtorr and temperatures between 450°–700°C, with titanium tetrachloride and ammonia as reactants. Both hydrogen and nitrogen are evaluated as diluents. Deposition rates as high as 1000 Å/min have been achieved. The chemical nature of the films are evaluated by Auger and RBS techniques, while the morphology is depicted by SEM. For the most part, the films are stoichiometric and contain small quantities of oxygen, chlorine, and hydrogen. Film resistivities as low as 50 μΩ‐cm are reported. Behavior of the TiN film as a diffusion barrier between silicon (boron doped) and aluminum, at annealing temperatures up to 550°C, is evaluated by measurements of contact resistance and diode leakage.