Investigation and Failure Analysis of "Flower-like" Defects on Microchip Aluminum Bondpads in Wafer Fabrication

In this paper, Al fluoride defects on microchip Al bondpads were studied, which were confirmed to be due to a 12 hours delay prior to NE111 clean process. Failure analysis results and mechanism were discussed. Moreover, a preventive solution of introducing a time link between passivation etch and NE111 clean process was recommended and implemented