A high-k dielectric metal trench capacitor and improved isolation and methods of manufacturing the same is provided. The method includes forming at least one deep trench in a substrate, and filling the deep trench with sacrificial fill material and a poly material. The method further includes continuing with CMOS processes, comprising forming at least one transistor and back end of line (BEOL) layer. The method further includes removing the sacrificial fill material from the deep trenches to expose sidewalls, and forming a capacitor plate on the exposed sidewalls of the deep trench. The method further includes lining the capacitor plate with a high-k dielectric material and filling remaining portions of the deep trench with a metal material, over the high-k dielectric material. The method further includes providing a passivation layer on the deep trench filled with the metal material and the high-k dielectric material.