Reduction of electrostatically adhered particles on wafer backside using ionizers

In this paper we provide results and discussion on the positive impact of ionizer(s) used in multiple configurations on wafer back-side and front-side particle adders in PVD processing tools. We present a hypothesis, followed by testing, that establishes a relationship between electrical surface charge collection data and particle data obtained in a laboratory setting and real world fabrication facility (fab) environment. For chip manufacturers, controlling surface charges on production wafers results in a reduced number of undesirable particles, thereby resulting in higher yield, more reliable final product chips, and reduced product losses. And for equipment manufacturers, more reliable and better tool performance can lead to increased customer satisfaction. The INOVA^® PVD system's good particle performance, as demonstrated on good quality wafers, is made more robust with an ionizer installation when marginal quality wafers are used.