An investigation on the plasma treatment of integrated circuit bond pads

Abstract

Integrated circuit (IC) bond pads play an important role in the wire bond reliability of the microelectronic devices. Being the device’s only electrical connection to the package and electronic systems, it is mandatory that the bond pads are free of contaminants and possess excellent bonding characteristics. Contaminants such as oxides and organic residues impair the bondability to a considerable extent and are very resistant to conventional wet cleaning methods. In this paper, we report the effects of an Ar/H 2 plasma treatment on the surface chemistry and morphology of IC bond pads. Surface and sub-surface chemical analyses have been conducted using Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Results reveal that the oxygen level of the bond pad surface has decreased significantly after the plasma treatment. Although the treatment has successfully removed the surface crystallites on the bond pads on prolong etching; however, the aggressive process has also damaged the passivation layers that surround the pad areas.