SEMICONDUCTOR DEVICE AND MANUFACTURE THEREOF

摘要

PURPOSE:To increase storage capacitance, to reduce the quantity of dry etching for forming a groove and to minimize damage to a substrate by forming a side- wall opening section in width wider than a surface opening section and using the inner wall of the side-wall opening section as an electrode surface. CONSTITUTION:An silicon oxide film 32 is patterned to the surface of an silicon substrate 31, and the silicon substrate 31 is dry-etched vertically while using the silicon oxide film 32 as a mask to shape an opening section 33. An silicon oxide film 34 is formed. The silicon oxide film 34 is etched in an anisotropic manner to leave the silicon oxide film 34 only on the side surface of the opening section 33. The silicon substrate 31 is etched in an isotropic manner from the base of the opening section 33 to shape a second opening section 35. The silicon oxide films 32 and 34 are removed, and a dielectric film 36 represented by a film such as the silicon oxide film is formed onto the surface of the silicon substrate and the surface of the opening section. A polycrystalline silicon film 37 is buried into the opening section.