Method for forming DRAM stack capacitor using silicon oxide etch barrier

摘要

There is provided a method of forming a stack capacitor of a dynamic random access memory. The stack capacitor is provided on the transistor and includes first and second electrodes and a dielectric film interposed therebetween. The first electrode acts as a storage node. The first silicon oxide film is deposited on the interlayer dielectric film on the transistor. The first silicon oxide film is provided to prevent etching of the interlayer insulating film. Then, an amorphous silicon film is deposited on the first silicon oxide film. The silicon film is used to form the storage node and has a density lower than the density of the first silicon oxide film. Thereafter, the second silicon oxide film is deposited on the silicon film. The second silicon oxide film is used to form the silicon film. The second silicon oxide film is selectively removed after the silicon film is formed using the second silicon oxide film.