A method for controlling the position of air gaps in intermetal dielectric
layers between conductive lines and a structure formed using such a
method. A first dielectric layer is deposited over at least two features
and a substrate and an air gap is formed between the at least two features
and above the feature height. The first dielectric layer is etched between
the at least two features to open the air gap. Then a second dielectric
layer is deposited over the etched first dielectric layer to form an air
gap between the at least two features and completely below the feature
height.
