Method for making a charge storage electrode for a semiconductor device

摘要

A method for making of a charge storage electrode in a semiconductor device is disclosed. The method comprises the steps of forming a first silicon film into a second protruded silicon film which is aslant at its both sides, forming a first thin insulating film over the second silicon film, and applying an anisotropic dry etching to the first insulating film and the second silicon film to form a vertical structure of a third silicon film, said anisotropic dry etching allowing the upper first insulating film to be removed prior to the side first insulating film, which subsequently remains in a thinner thickness to act as an obstacle to the anisotropic dry etching for the side portions of the protruded second silicon film, so that the central portion of the protruded second silicon film is etched in a larger quantity than the side portions. The silicon film which is an electroconductive material for a charge storage electrode is structured to be vertical in accordance with the present invention, so that it comes to have a larger surface area than a conventional one, thereby securing the capacitance of the charge storage electrode and making the charge storage electrode in an improved production efficiency.