A memory device, and a method of forming a memory device, is provided that includes a capacitor with a lower electrode of a metal semiconductor alloy. In one embodiment, the memory device includes a trench present in a semiconductor substrate including a semiconductor on insulating (SOI) layer on top of a buried dielectric layer, wherein the buried dielectric layer is on top of a base semiconductor layer. A capacitor is present in the trench, wherein the capacitor includes a lower electrode of a metal semiconductor alloy having an upper edge that is self-aligned to the upper surface of the base semiconductor layer, a high-k dielectric node layer, and an upper electrode of a metal. The memory device further includes a pass transistor in electrical communication with the capacitor.