Effect of annealing temperature on structural and electrical properties of tantalum nitride thin film resistors deposited on SiO2/Si substrates by dc sputtering technique

Tantalum nitride thin films were deposited on SiO2 (600 nm)/Si substrates at 200 degrees C and a nitrogen/argon flow ratio of 3% by dc sputtering technique and then were annealed at various temperatures in vacuum and nitrogen ambients. For the films annealed in both vacuum and nitrogen ambients, the effect of annealing temperature on structural and electrical properties of the films was systematically investigated. Crystallinity of the films was significantly improved as annealing temperature increased. Temperature coefficient of resistance (TCR) of the films was varied from a negative value to a positive value with increasing annealing temperature in both vacuum and nitrogen ambients. The variation of TCR with annealing temperature in both vacuum and nitrogen ambients was due to the improved crystallinity rather than a nitrogen concentration in the films. Irrespective of annealing temperature, the films annealed at various temperatures do not exhibit the irreversibility of resistance. (c) 2006 American Vacuum Society.