METHOD FOR MANUFACTURING A CYLINDRICAL CHARGE STORAGE ELECTRODE

摘要

PURPOSE: A method for forming a cylindrical type storage electrode is to enlarge surface area of the storage electrode by providing of unevenness to the sidewall thereof using a wet-etching ratio of grain boundary between the micro-grains of polysilicon, thereby improving reliability of a semiconductor substrate. CONSTITUTION: An undoped oxide layer is deposited on an interlayer dielectric(107). The interlayer dielectric and the undoped oxide layer are etched to form a contact hole for storage electrode. The first amorphous silicon layer is deposited on the resultant structure including the contact hole. A doped oxide layer is deposited on the first amorphous silicon layer. The doped oxide layer and the first amorphous silicon layer are successively etched by using the storage electrode as a mask. The second and third doped amorphous silicon layers are deposited on the resultant structure, and then etched to form a spacer(106). The undoped and doped oxide layers are removed. The spacer is wet-etched in etching solution to provide the surface thereof with unevenness after crystallizing the first/second/third amorphous silicon layers by an annealing.