LOWER ELECTRODE OF CAPACITOR AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: A lower electrode of a capacitor and a manufacturing method thereof are provided to largely increase a capacitance by increasing a surface of the lower electrode of an MIS(Metal Insulator polySilicon) or MIM(Metal Insulator Metal) capacitor as using a metallic material which becomes uneven by the heat for the lower electrode. CONSTITUTION: A trench as an area designed for the lower electrode is formed on a semiconductor substrate(10). A doped polysilicon(16) as a conductive layer is formed on the trench after forming a diffusion barrier film(14). A thin film of the metal becomes uneven by the heat is deposited on the doped polysilicon and an annealing process is performed in order to make the metal uneven. A diffusion barrier film is formed on an upper part of the lower electrode(b) having a concave-convex metal surface. A trench type capacitor is formed by forming a dielectric film and an upper electrode on the diffusion barrier film.