“…The TSV process comprises via etching, via insulation, deposition of the diffusion barrier/liner/seed, deposition of the metal/alloy to fill the TSV, followed by appropriate thermal processing and removal of any overburden. Extensive work has been done in the fabrication, integration, and characterization of TSVs (27,(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47). The TSVs may be etched first before any other process, or last, from the backside of thinned wafer, as shown in Figure 7 compared very deep TSVs, in the 100 μm range, with AR approaching 50:1 in the FEOL (29).…”