A Comparison of TSV Etch Metrology Techniques

Guillaume Vienne (1) , Laurent Milord (1) , Jean-Philippe Piel (2) , Wolfgang Iff (3) , Philippe Coste (4) , Astrid Sippel (1) , Tristan Combier (1) , Alexandre Tarnowka (1) , Jean-François Boulanger (1) , Georges-Olivier Reymond (1) , Dario Alliata (1) , Alain Bosseboeuf (4)

1 UnitySC - UnitySC
2 FOGALE NANOTECH - Fogale nanotech
3 Laboratoire Charles Fabry / Naphel
4 C2N (UMR_9001) - Centre de Nanosciences et Nanotechnologies

We use three metrology techniques, vertical scanning interferometry (VSI), confocal chromatic microscopy (CCM), and time domain optical coherence tomography (TD-OCT), for depth measurement of through-silicon vias (TSVs) of various cross sections and depths. The merits of these techniques are discussed and compared. Introduction While sales of semiconductor equipment broke a new record this year, many metrology needs should be addressed to support the development and production of electronic chips based on "More than Moore" scaling. Among these scaling approaches, 3D integration based on TSVs offers superior integration density and reduces interconnect length/latency. Measurements are needed to evaluate the depth uniformity of etched TSVs. Indeed, upon metal filling, geometrical variations of TSVs can affect Cu nails coplanarity and can warp the wafer, resulting in a low stacking yield. Measuring the depth of TSVs is an increasingly challenging task as the diameter of many TSVs has now shrunk to only a few microns.

Domaines: Micro et nanotechnologies/Microélectronique; Optique / photonique

Guillaume Vienne, Laurent Milord, Jean-Philippe Piel, Wolfgang Iff, Philippe Coste, et al.. A Comparison of TSV Etch Metrology Techniques. European Optical Society Biennal Meeting (EOSAM), Oct 2018, Delft, Netherlands. ⟨hal-02343393⟩