Adhesion promoter internal

What is accomplished by adhesion promotion treatments in IC manufacturing should actually be referred to as wafer substrate preparation, and not adhesion. Adhesion in the structural sense, as experienced in airplane composite material parts attachment, is not accomplished by silane wafer processing treatments except for the PI applications discussed early in this paper. The term adhesion, as it is used here, refers to a more practical definition—that is, resist image adhesion. Nevertheless, this type of adhesion is essential to the huge international semiconductor business, and the early silane work of Plueddemann and others was essential to early wafer adhesion process development. 

The main difference between primers and adhesion promoters is that primers are liquids that are applied to the substrate as a relatively heavy surface coating prior to application of the adhesive. Adhesion promoters, on the other hand, are liquids that form a very thin (usually monomolecular) layer between the substrate and the adhesive. Usually chemical bonds are formed (1) between the adhesion promoter and the adhesive and (2) between the adhesion promoter and the substrate surface. These bonds are stronger than the internal chemical bonds within the adhesive. These new bonds also provide an interface region that is more resistant to chemical attack from the environment. Adhesion promoters are also sometimes referred to as coupling agents. 

Copper films for the polishing experiments were sputter deposited using a TORR International CRC-150 sputtering system on 6" blanket silicon wafers with tantalum as the adhesion promotion layer. The resistivity of the sputtered copper films was determined to be 2.5 jX2 cm. The slurries for the polishing experiment were prepared using a-alumina particles, with a bulk density of 3.7 g/cc, obtained from Ferro Corporation. The solids concentration was kept at 2 wt % unless otherwise stated. All the chemicals were purchased from Aldrich chemical company and were used without further purification. 

P. K. Jenkner Second International Symposium on Silanes and Other Adhesion Promoters, Newark, October 1998. 

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