An embodiment is a method including forming a first interconnect structure over a first substrate, the first interconnect structure comprising dielectric layers and metallization patterns therein, patterning the first interconnect structure to form a first opening, coating the first opening with a barrier layer, etching a second opening through the barrier layer and the exposed portion of the first substrate, depositing a liner in the first opening and the second opening, filling the first opening and the second opening with a conductive material, and thinning the first substrate to expose a portion of the conductive material in the second opening, the conductive material extending through the first interconnect structure and the first substrate forming a through substrate via.