LIQUID SOURCE METALORGANIC CHEMICAL VAPOR-DEPOSITION OF ALUMINUM FROM TRIETHYLAMINE ALANE

Low-pressure metalorganic chemical vapor deposition (MOCVD) of aluminum using triethylamine alane (TEAA) is reported. This liquid source combines the chemical advantages of adduct precursors such as solid trimethylamine alane (TMAA), with the processing and handling advantages of liquid precursors such as triisobutyl aluminum (TIBA). High-purity Al films were deposited on TiN and thin in situ evaporated Cu and Ti films, which serve as activators for nucleation of Al. The electrical resistivities of the Al films on TiN were closed to the 3-mu-OMEGA cm of sputtered Al. In the case of depositions on Cu, the Cu diffuses readily into the Al and serves to improve the electromigration resistance of the latter. The Al deposition rates using TEAA are 2-4 times those using TIBA at 250-degrees-C, although the TEAA process is not fully optimized at this point and further work is needed to improve the film morphologies.