Die attach failures related to wafer back metal processing—an AES study

Die attach failures on Cr/Ni/Au back-metallised silicon wafers have been studied under different process conditions. The Auger studies on the failed devices show that the formation of nickel oxide causes poor die attachment even for an Au film thickness of ∼ 500 Å. The failures simulated experimentally revealed that nickel oxide formation depends on the film sintering conditions.