| CPC H01L 23/481 (2013.01) [H01L 21/76843 (2013.01); H01L 21/76898 (2013.01); H01L 23/5226 (2013.01); H01L 23/5283 (2013.01)] | 20 Claims | 

| 
               1. A method, comprising: 
            forming a semiconductor device on a front surface of a substrate; 
                forming a first interconnect structure on the front surface of the substrate; 
                performing a thin down process on a back surface of the substrate; 
                forming a first portion of a second interconnect structure on a back surface of the thinned down substrate; 
                forming a through-via opening extending through the first portion of the second interconnect structure, the substrate, and the first interconnect structure; 
                depositing a conductive liner along sidewalls of the through-via opening; 
                depositing a conductive plug on the conductive liner; and 
                forming a second portion of the second interconnect structure on the conductive plug. 
               |