Abstract In wafer fabrication, Fluorine (F) contamination may cause fluorine-induced corrosion and defects on microchip Aluminum (Al) bondpads, resulting in bondpad discoloration or non-stick on pads (NSOP). Auger Electron Spectroscopy (AES) is employed for measurements of the fluorine level on the Al bondpads. From a Process control limit and a specification limit perspective, it is necessary to establish a control limit to enable process monitor reasons. Control limits are typically lower than the specification limits which are related to bondpad quality. The bondpad quality affects the die bondability. This paper proposes a simulation method to determine the specification limit of Fluorine and a Shelf Lifetime Accelerated Test (SLAT) for process monitoring. Wafers with different F levels were selected to perform SLAT with high temperature and high relative humidity tests for a fixed duration to simulate a one year wafer storage condition. The results of these simulation results agree with published values. If the F level on bondpad surfaces was less than 6.0 atomic percent (at%), then no F induced corrosion on the bond pads was observed by AES. Similarly, if the F level on bond pad surfaces was higher than 6.0 atomic per cent (at%) then AES measured F induced corrosion was observed.

Abstract This paper illustrated the beauty of AFP nano-probing as the critical failure analysis tool in localizing new product design weakness. A 40nm case of HTOL Pin Leakage due to Source/Drain punch-through at a systematic location was discussed. The root cause and mechanism was due to VDS overdrive testing issue. This paper placed a strong emphasis on systematic problem solving approach, deep dive and use of right FA approach/tool that are essentially critical to FA analysts in wafer foundry since there is always minimal available data provided. It would serve as a good reference to wafer Fab that encountered such issue.