Patent ID: 7833895
Filing Date: 2010-11-16
Classification: H01L

Abstract:
1. A method for fabricating integrated circuits (ICs) including via-first through substrate vias (TSVs), comprising: providing a bulk silicon comprising substrate having a substrate thickness comprising a top silicon surface and a bottom silicon surface opposite said top silicon surface including at least one embedded TSV having an embedded TSV tip in said bulk silicon comprising substrate, said embedded TSV tip extending from said top silicon surface to a via depth that is less than said substrate thickness, said embedded TSV including a dielectric liner and an electrically conductive filler material formed on said dielectric liner; mechanical removing a portion of said substrate from said bottom surface of said substrate to approach but not reach said embedded TSV tip, wherein a protective substrate layer having a protective layer thickness from 2 μm to 10 μm remains over said embedded TSV tip after said mechanical removing; and chemical etching exclusive of mechanical etching for removing said protective substrate layer to form an protruding integral TSV tip that protrudes from said bottom silicon surface, said protruding integral TSV tip comprising said electrically conductive filler material extending out a tip height from 10 to 40 μm and including a dielectric tip liner on said electrically conductive filler material for 10 to 90% of said tip height to provide an exposed tip portion, wherein said chemical etching comprises: a first chemical etch for etching said silicon on said bottom silicon surface to at least reach said via depth to expose said dielectric liner while avoiding exposing said electrically conductive filler material on said protruding integral TSV tip; a second chemical etch for etching said dielectric liner off said protruding integral TSV tip to expose said exposed tip portion of said protruding integral TSV tip; and a third chemical etch for etching said silicon from said bottom silicon surface to achieve said tip height for said protruding integral TSV tip.