MANUFACTURING METHOD OF CHARGE STORAGE ELECTRODE WITH ENLARGED SURFACE

摘要

forming a thick BPSG layer, nitride layer and oxide layer on a substrate on which a MOS transistor is formed, forming a contact hole to expose the source region of the MOS transistor, forming a first silicon layer, second silicon layer and third silicon layer on the overall surface of the substrate, carrying out heat treatment to form hemispherical grains on the surface of the third silicon layer, patterning the third, second and first silicon layers to form fin-structure charge storage electrode, removing the oxide layer to expose a under portion of the first silicon layer, and carrying out heat treatment to form hemispherical grains for the exposed under portion of the first silicon layer.