A new interlayer dielectric (ILD) cracking mechanism in ceramic packaged multilayered CMOS devices

摘要

A new interlayer dielectric (ILD) cracking mechanism was uncovered in a multilayered CMOS technology. This new mechanism was found in ceramic packaged ICs and differs from the well known thermal cycling induced thin-film cracking (TFC) found in plastic packaged ICs. It is shown that the driving force for this new mechanism is a combination of wire bonding stress and wide metal bus layout. A new TFC design specification was developed to prevent the recurrence of the same mechanism on subsequent hermetic packaged products. The reliability impact of this cracking mechanism is reported and investigated in this paper.