Characterization of interfacial reactions between ionized metal plasma deposited Al-0.5 wt.% Cu and Ti on SiO2

It was reported that the reaction between Al and Ti takes place and Al3Ti compound is formed during the annealing at 500 degrees C. Annealing at higher temperatures, such as 550 and 600 degrees C, the Al3Ti compound transforms to Al5Ti2. It is believed that the Al5Ti2 is thermodynamically stable comparing with Al3Ti. In the present research, the interfacial reactions in Al-0.5 wt.% Cu/Ti/SiO2/Si structure have been investigated in the samples prepared by ionized metal plasma (IMP) and then annealed at various temperatures from 200 to 600 degrees C for 30 min in Argon ambient. The results obtained by Rutherford backscattering spectroscopy and transmission electron microscopy show that there is a Ti layer (52 nm in thickness) between Al2Ti2 and SiO2 and there is no formation of the ternary compound - AlxTiySiz, which is detrimental in the contact metallization layer. It indicates that the Ti layer deposited by IMP technique acts as a barrier to retard the reaction between Al5Ti2 and SiO2 and consequentially protect the contact metallization layer. (C) 2000 Elsevier Science S.A. All rights reserved.