Semiconductor structure and method of fabrication including forming aluminum columns

A method of forming aluminum conductors over a semiconductor structure comprising a semiconductor body having defined therein and formed on a top surface thereof contact regions to which electrical contacts are to be made, a first plurality of electrical conductors which have first ends that contact the contact regions, which extend above the top surface of the semiconductor body and are electrically isolated from each other by portions of a first insulating layer, and which have second ends which are in an essentially common plane, the method comprising the steps of:

• forming a second insulating layer over the first insulating layer;
• forming vias through the second insulating layer with each via being in communication with one of the first plurality of electrical conductors;
• covering sidewalls and a bottom of each of the vias through the second insulating layer with a conductive layer;
• covering each conductive layer with a nucleation layer of chemical vapor deposited aluminum;
• overfilling each of the vias through the second insulating layer with physical vapor deposited aluminum deposited at a temperature below the melting point of aluminum but close enough such that the deposited aluminum fills the vias through the second insulating layer and forms a blanket layer of aluminum above a top surface of the second insulating layer;
• applying a patterning layer over the blanket layer of aluminum which leaves surface portions thereof uncovered;
• removing aluminum in the areas not covered by the patterning layer to leave columns of aluminum which extend into the vias of the second insulating layer;
• and
• forming a third insulating layer around the columns of aluminum.