Keniti Imamiya

Optimum redundancy design for new-generation EPROMs based on yield analysis of previous generation

Failure modes of 4 Mbit EPROMs have been analyzed, and the model to formulate them is proposed. The redundancy scheme of a 16 Mbit EPROM was optimized by the model in consideration of area penalty. In applying the 4 Mbit data to 16 Mbit EPROM, fabrication line improvement was taken into account. The actual data of 16 Mbit EPROM failure analysis indicate the effectiveness of the prediction. The 16 Mbit EPROM has 2 rows*8 blocks redundancy, and the redundancy gives the highest yield in the time when the mass production begins.<<ETX>>