Semiconductor memory device and method of checking same for defect

摘要

A semiconductor memory device includes a first test row decoder (9a) for selecting memory cells in normal rows in a test mode, a second test row decoder (9b) for selecting spare memory cell rows, a first test column decoder (10a) for selecting memory cells in normal columns, and a second test column decoder (10b) for selecting spare memory cell columns. A control circuit (11) may perform switching between four combinations of the row and column decoders by using a control signal (SRT) and a control signal (SCT). All spare memory cells are tested prior to reparation of a defective memory cell for yield enhancement.