Investigation of aluminium bondpad metal peeling failure

Aluminium bondpad metal peeling due to the poor adhesion between the metal and underlying poly layer is presented. Failure analysis results showed that the non-uniformity of WSix layer is the root cause for the poor adhesion. In this paper, we will discuss the details of failure analysis using SEM, EDX, FIB, Auger and TEM. We will also report the corrective and preventive actions, which serve as a good reference to other wafer fab and assembly houses.