Surface characterization of the Al/Si-Ti/W metallization after chlorinated plasma treatments

Multilayer metallizations play a very important role as interconnection systems in the VLSI technology. Here, to realize etching with good dimensional control and vertical profile, plasma etchers (of the RIE type) are used. The complexity of the chemistry involved in this plasma etching is such that it may give rise to some undesirable secondary effects. The object of this work is the surface characterization, by means of XPS, SEM, and EDAX techniques, of the Al/Si-Ti/W system after plasma etching. The chemical modifications induced by various plasma treatments of the metal films have been followed by means of the above techniques. Such modifications are dependent either on the etch chemistry used or on the substrate chemical species exposed to the plasma.