Unique nondestructive inline metrology of TSVs by X-ray with model based library method

Abstract

Unique nondestructive inline profile metrology of through-Silicon via (TSV) for 3D integrated circuits in production processes such as ultra-deep etching and Cu pillar forming process was introduced. We tried to measure the depth profile of TSVs from X-ray images with a tilted angle by applying model based library method. The fairly good repeatability in critical dimensions (CDs) and the depths (<;100nm, <;200nm respectively) and good correlation in CDs with results from SEM measurement were obtained, and good robustness under low SNR ~2 of the images was confirmed.