Solutions for forming a silicided deep trench decoupling capacitor are disclosed. In one aspect, a method of forming a semiconductor device includes: forming an outer trench in a silicon substrate, the forming exposing portions of the silicon substrate below an upper surface of the silicon substrate; depositing a dielectric liner layer inside the trench; depositing a doped polysilicon layer over the dielectric liner layer, the doped polysilicon layer forming an inner trench in the silicon substrate; forming a silicide layer over a portion of the doped polysilicon layer; forming an intermediate contact layer within the inner trench; and forming a contact over a portion of the intermediate contact layer and a portion of the silicide layer.