Characterization of Al/Cu/W bond pad micro-corrosion

Abstract

In this paper, micro-corrosion of Al/Cu/W bond pad was studied. During DI water cleaning process, theta phase Al2Cu and surrounding Al performed well as typical galvanic cell, resulting in pad metal micro-corrosion. DI water with Pb2+ is thought to be outside electrical path of the galvanic cell. It is firmly believed that Pb-contained particles on top of Al2Cu and surrounding Al oxide and/or hydroxide were the cathodic and anodic reaction product respectively.