METHOD FOR FORMING A CAPACITOR OF SEMICONDUCTOR MEMORY

摘要

PURPOSE: A fabrication method of capacitors using a ferroelectric substance having residual polarization property is provided to improve a hysteresis loop by restraining Bi volatile of SBT film and preventing chemical reaction between an insulator and the SBT film CONSTITUTION: The method comprises the steps of sequentially forming a lower electrode(14) and an SBT ferroelectric film(15) on a silicon substrate(11); patterning the SBT ferroelectric film(15) and the lower electrode(14); depositing SrTiO3 layer(16) on the SBT ferroelectric film(15) to be entirely surrounded by CVD(chemical vapor deposition) at 300-550°C, thereby stabilizing the SBT ferroelectric film(15) and preventing Bi volatile; etching the SrTiO3 layer(16) to expose the SBT ferroelectric film(15); and forming an upper electrode(17) on the exposed SBT ferroelectric film(15).