Abstract: A method is provided for forming electrodes of a trench capacitor for an integrated circuit in which the number of mask levels is reduced. The method is compatible with CMOS and Bipolar CMOS processes. After defining a trench in a substrate by a conventional photoengraving step and anisotropic etching, successive conformal layers of a first dielectric layer, a first conductive layer, and subsequent conformal dielectric layers and conformal conductive layers are deposited to fill the trench. The resulting structure is planarized, preferably by chemical-mechanical polishing to provide fully planarized topography. Each of the conductive layers form an electrode. Coplanar areas of each of the conductive layers are exposed within the trench for formation of contacts to the electrodes. Advantageously, the trench has a wide portion and a narrow portion of smaller lateral dimension.

Abstract: A method is provided for forming electrodes of a trench capacitor for an integrated circuit in which the number of mask levels is reduced. The method is compatible with CMOS and Bipolar CMOS processes. After defining a trench in a substrate by a conventional photoengraving step and anisotropic etching, successive conformal layers of a first dielectric layer, a first conductive layer, and subsequent conformal dielectric layers and conformal conductive layers are deposited to fill the trench. The resulting structure is planarized, preferably by chemical-mechanical polishing to provide fully planarized topography. Each of the conductive layers form an electrode. Coplanar areas of each of the conductive layers are exposed within the trench for formation of contacts to the electrodes. Advantageously, the trench has a wide portion and a narrow portion of smaller lateral dimension.