One aspect of the disclosure relates to an interposer. The interposer may include: a first dielectric layer extending from a substrate in a direction away from a front side of the substrate; a back-end-of-the-line (BEOL) region extending from the substrate in a direction away from the back side of the substrate; a deep trench (DT) capacitor within the substrate and extending toward a back side of the substrate, the DT capacitor having a first portion within the substrate and a second portion within the first dielectric layer; and a through silicon via (TSV) adjacent to the DT capacitor and extending through the first dielectric layer, the substrate, and the BEOL region.