New Front Side Access Approach for Low-k Dielectric/Cu Technologies in Plastic Package

This paper presents a new sample preparation process for front side access for die with organic dielectric layers that are encapsulated in plastic packages. The limitation of the standard failure analysis flow is firstly described, showing the damage caused by wet etching. Then, the decapsulation method combining laser ablation and plasma etching is presented. It is completed by the process optimization. The final process makes it possible to perform failure analysis on low-k/Cu technologies in plastic package either by the front side or by the backside of the die.