METHOD FOR FABRICATING FLOATING TRAP FERAM

摘要

PURPOSE: A method for fabricating a floating FeRAM is provided to simplify the production process and enhance reliability of storing data. CONSTITUTION: A thick silicon oxide layer is formed on a substrate(100) for high voltage. After patterning the silicon oxide layer by photolithography, a silicon oxide layer pattern(111') is left only on the high voltage region. The first photoresist pattern is removed and then an ONO layer with an upper and lower oxide and a nitride layer are patterned by photolithography. The second photoresist pattern is removed and then a thermal oxidation process is performed on the whole surface of the substrate. A thin thermal oxide layer(181) is formed on a low voltage region while the thickness of thermal oxide layer is increased on a high voltage region.