In wafer fabrication, silicon defects on the substrate directly affect the yield of the wafer. In this paper, we will study and discuss a chemical delayering and delineate method for silicon defects in wafer fabrication using Secco etch. It is well-known that during delayering process of wafer, the removal of polysilicon (Poly-Si) layer is very difficult, especially for the wide-layer polysilicon (Poly-Si) which is difficult to completely remove with HF acid solution. We introduce a chemical recipe to fast delayer polysilicon layer completely before delineating silicon defects on silicon substrate using Secco etch. Those skilled in the art could be experiment within half an hour to get analysis results. It saves time and improves operational efficiency. Moreover, based on the experimental results we think that it is possible to identify the root cause according to the shapes of silicon defects using Secco etch.

Currently, wire bonding is still the dominant interconnection mode in microelectronic packaging, and epoxy molding compound (EMC) is the major encapsulant material. Normally EMC contains chlorine (Cl) and sulfur (S) ions. It is important to understand the control limit of Cl and S in the EMC to ensure good Au wire bond reliability. This paper discussed the influences of Cl and S on the Au wire bond. Different contents of Cl and S were purposely added into the EMC. Accelerated reliability tests were performed to understand the effects of Cl, S and their contents on the Au wire bond reliability. Failure analysis has been conducted to study the failure mechanism. It is found that Cl reacted with IMCs under humid environment. Cl also caused wire bond failure in HTS test without moisture. On the other hand, the results showed that S was not a corrosive ion. It was also not a catalyst to the Au bond corrosion. Whilst, high content of S remain on the bond pad hindered the IMCs formation and caused earlier failure of the wire bond.