Daniel Lawrence Adams

Titanium Nitridation on Copper Surfaces

Cu{sub 74}Ti{sub 26} alloy films were annealed in flowing NH{sub 3} at temperatures of 450 to 700 C. Ti segregates to the free surface to form TiN, leaving nearly pure Cu in the remaining metal film. Elastic recoil detection and Auger electron spectroscopy were applied to investigate the chemistry of the as-formed nitride as a function of anneal temperature. The use of these two techniques in tandem offers a combination of standardless compositional determination, excellent mass and depth resolution, and chemical bonding information. The Ti:N ratio is nearly 1.0 for T {ge} 550 C, and the nitride contains {approximately}6 atom percent O. The amount of nitrogen incorporated increases with temperature with an activation energy of 0.6 eV. A native Ti oxide remaining at the TiN/Cu interface suggests Ti is the dominant diffusing species during nitridation.