Cu films grown using metalorganic chemical vapor deposition were investigated as a function of barrier material. In particular, the minimum thickness (t(crit)) at which the copper film became continuous in a high aspect ratio feature was determined to depend strongly on the underlying barrier material and properties. When the CVD Cu film was deposited directly on the barrier material, the tri, was > 200 Angstrom, whereas with the addition of a more conductive nucleation layer a t(crit) as low as 100 Angstrom was achieved. The correlation of t(crit) to microstructural and mechanical properties was also investigated.

Adhesion energies of Cu-low k dielectric interfaces, measured with the technique of four-point bending, show a correlation to chemical mechanical polish results. A limit of 5 J/m(2) is established, below which thin film delamination and cracking are observed. In general, spin-on polymer dielectrics exhibit better adhesion to barrier films than carbon-doped oxide dielectrics. PVD barriers exhibit better adhesion to low k dielectric films than CVD barriers. Surface treatments of the dielectric film before barrier deposition are found to strongly modulate CVD barrier to spin-on polymer adhesion.

Electroplated Cu is being used by the major semiconductor manufacturers as an interconnect material, because it offers a lower line resistance and better electromigration performance over conventional Al metallization. This paper describes the mechanism of "super-fill" as well as gap fill, microstructure, and film composition of electroplated copper. A combination of optimized Cu plating additive chemistry and current waveform enable complete gap fill of 0.07-0.1 /spl mu/m features (AR>10:1) as well as strong [111] texture, large grains (>3 /spl mu/m) with a large fraction of twin grain boundaries and controlled impurity content in electroplated Cu films. Electroplating process stability was maintained through the on-line analysis (p/t<0.3) of organic and inorganic bath ingredients and their replenishment.