Method of fabricating contact openings for dynamic random-access memory

摘要

A method of making contact openings for memory cell units of DRAM IC devices is disclosed. The contact opening is used to connect the cell transistor source/drain terminal to the storage capacitor electrode located substantially above. The method includes the step of first patterning the initial opening in a shielding layer for the contact opening. The diameter of the initial opening is then reduced by the formation of sidewall spacers in initial opening. The initial opening in the shielding layer is then used to implement the etching for the formation of the contact opening. Due to reduced size of the contact opening, short-circuiting situations arising between the via formed in the contact opening and the bit lines next to the via as a result of misalignment in the process of fabrication can be reduced, thereby improving the device fabrication yield rates.