FORMING THROUGH-SILICON-VIAS FOR MULTI-WAFER INTEGRATED CIRCUITS

摘要

The present invention provides a method for forming a three-dimensional wafer stack having a single metallized stack via with a variable cross-sectional shape. The method uses at least first and silicon wafers. Each wafer has one or more integrated circuits formed thereon. One or more through-vias are formed in each silicon wafer followed by oxide formation on at least an upper and lower surface of the silicon wafer. The wafers are aligned such that each wafer through via is aligned with a corresponding through via in adjacent stacked wafers. Wafers are bonded to form a three-dimensional wafer stack having one or more stack vias formed from the alignment of individual wafer vias. Via metallization is performed by depositing a seed layer in each of the stack vias followed by copper electroplating to form a continuous and homogeneous metallization path through the three-dimensional wafer stack.