A trench capacitor manufacturing method is provided. The method includes forming a deep trench in a wafer, forming a trench capacitor structure including a plurality of dielectric films and a plurality of conductive layers in the deep trench; determining if the wafer has a tensile stress based on the forming of the trench capacitor structure; performing a high temperature heat treatment to the trench capacitor structure to change a form of the wafer to a direction that offsets the tensile stress; forming an inter-layer insulating film on the trench capacitor structure; and forming a metal interconnect on the inter-layer insulating film.