Method of improving the texture of aluminum metallization for tungsten etch back processing

摘要

A method of making connection between an aluminum or aluminum based material and tungsten. The method includes providing an underlying region containing a layer of tungsten thereover. The underlying region is preferably a layer of titanium over which is a layer of titanium nitride. The layer of tungsten is etched back to the underlying region while exposed tungsten is retained over a portion of the underlying region. The underlying region also may contain a via therein which contains the exposed tungsten. An nitrogen-containing plasma, preferably elemental nitrogen, is then applied to the exposed tungsten and exposed underlying region and a layer of a barrier material is formed by reaction of the nitrogen in the plasma and the tungsten over the exposed tungsten. A further barrier layer, preferably titanium nitride, is optionally then applied followed by a layer of aluminum over the exposed surface, the barrier layer isolating the layer of aluminum from the tungsten. Plasma is preferably an argon/nitrogen plasma.