Flash EEPROM fabrication process that uses a selective wet chemical etch

摘要

A method for wet etching disposable spacers in silicon integrated circuits is provided. Illustratively, a pair of spacers is formed over a polysilicon substrate. A second pair of spacers is formed from doped silicon dioxide over the first pair of spacers. Then the second pair of spacers is etched away with NH4OH/H2O2, thus providing a means for defining the underlying polysilicon layer, e.g., by etching.