Redundancy circuit and repair method for a semiconductor memory device

摘要

A redundancy circuit and repair method for a semiconductor memory device. The redundancy circuit comprises an address buffer for outputting a first internal address and a second internal address (used only during redundancy programming to carry failed memory addresses) based on an external address; and address storage and comparison units, each one of the address storage and comparison units being selected for programming using the second internal address. The address storage and comparison units comprise ferroelectric storage cells that store the address of a defective (failed) main memory cell and outputs a redundancy decoder enable signal in response to a first internal address matching the stored (second internal) address. Accordingly, the redundancy circuit with ferroelectric storage cells and a repair method allows the performance of a second repair when a defective cell is detected after a first repair or after a packaging process.