Abstract
Damage on the top metal layer caused by backend packaging processes often results in unlocalizable electrical failures like column select fails in DRAM products. Consequently, crosssections through an exact address are unhelpful. Decapping from the front side of the die by removing the package (Top- Down preparation), only uncovers the damaged die area. The root cause is removed with the package. A preparation method that preserves the package at the failure (Bottom-Up preparation) is necessary. This paper presents a preparation method for investigations and assessment of backend related problems by removal of the Si-die from the back side, leaving the package and connections layers free for a quick and reliable review. Typical applications described here are the localization of imprint-originated fails or monitoring of the bonding processes.
