Pre bonding metrology solutions for 3D integration

This article reports the capability and the recent development of optical profilometry for monitoring 3D integrated circuits. In particular, the capability to profile transparent film stacks, which was quite challenging, is now accessible with the Unifire optical profilometer from Nanometrics. It is demonstrated that the obtained information in term of topography and edge roll off is paramount to improving the 3D integration process. In addition, the implementation of Nanometrics' Advanced Film Capability (AFC) and/or Index Corrected Topography (ICT) may enable more detailed mapping of local within die film thickness and topography respectively.