Exploring the Correspondence Between Chemical States and Adhesion Property for Cr, Co Metal/AZ 4620, BCB Polymer Interface

A method is built for describing the relationship between adhesion strength and chemical states of Co/polymer and Cr/polymer interfaces. Based on the chemical bonding model, the adhesion strength is confirmed to be dominated by the metal-organic complex at the interfaces. For Cr/polymers interfaces, the formation of metal-organic complex is restricted by the oxidation of metal atoms during deposition, which leads to almost no variation in adhesion from low [benzocyclobutene(BCB)] to high (AZ 4620) oxygenated polymers. On the other hand, a strong adhesion is observed at the Co/BCB interface that arises from the metal-organic bonds associated with hydroxyl groups in the polymer. The method is expected to provide clear analysis to other metal-polymer interfaces for seeking proper combination in heterogeneous integration.