THE EFFECTS OF PROCESSING PARAMETERS IN THE LOW-TEMPERATURE CHEMICAL-VAPOR-DEPOSITION OF TITANIUM NITRIDE FROM TETRAIODOTITANIUM

Key findings are presented from a systematic study aimed at establishi ng a fundamental understanding of precursor decomposition pathways and resulting film nucleation and growth kinetics in the chemical vapor d eposition of titanium nitride from tetraiodotitanium. As part of the s tudy, key process parameters were varied systematically in order to de termine process activation energy and establish corresponding function ality curves for film purity, growth rate, structure, and morphology. The key process parameters studied were substrate temperature, source temperature, hydrogen carrier gas flow, and reactor pressure. Correspo nding findings indicated that all four parameters showed a direct and significant effect on film quality. Additionally, a thorough evaluatio n of resulting film composition, texture, and electrical properties le d to the identification of a wide process window for the growth of TiN films with optimized characteristics and performance. In this process window the TiN films were nitrogen-rich, with iodine concentrations b elow 2 atom %, displayed resistivities in the range 100 to 150 mu Omeg a cm, depending on thickness, and exhibited excellent step coverage, b etter than 90% conformality in both nominal 0.45 mu m, 3:1 aspect rati o and 0.25 mu m, 4:1 aspect ratio contact structures.