METHOD OF FORMING DIFFUSION PREVENTION LAYER OF CAPACITOR IN FERROELECTRIC MEMORY ELEMENT

摘要

PURPOSE: A method of forming a diffusion prevention layer of a capacitor is to deposit a thin film at a low temperature and deposit a relative thick film in a high temperature, thereby preventing an increased roughness of an upper electrode and the generation of a hillock. CONSTITUTION: A method of forming a diffusion prevention layer of a capacitor in a ferroelectric memory element comprises the steps of; forming a capacitor having an under electrode(20A), a ferroelectric film and an upper electrode(22A) on a semiconductor substrate(10); forming the first diffusion prevention layer(24) on the resultant created by forming the capacitor with a predetermined temperature; and forming the second diffusion prevention layer(26) thicker than the first diffusion prevention layer. The temperature for forming the second diffusion prevention layer is higher than the predetermined temperature. The thickness of the first diffusion prevention layer is within the range of about 100 to 200 angstrom, and the thickness of the second diffusion prevention layer is within the range of about 300 to 900 angstrom.