Contamination analyses of Al bond pads using FIB/SEM/EDX

Aluminum bond pads on semiconductor chips play an important role in IC device reliability and yield. Contaminated Al bond pads can cause poor intermetallic growths, thus failed or unreliable connections from the chip to the outside world. Utilizing FIB, SEM and EDX techniques, the contamination analysis may be carried out to reveal and identify defects underneath Al layer. In this study, three cases of Al bond pads with underneath contamination were investigated using this analysis approach. Based on the FIB/SEM/EDX analysis results, contamination root causes are discussed and suggested.