Semiconductor memory device and defective judging method thereof

Abstract

A semiconductor memory device is provided with a plurality of memory cells connected to a plurality of word lines, a word-line leakage detector configured to detect a leakage current generated on at least one of the plurality of word lines, and a controller configured, when a leakage current is detected by the word-line leakage detector, to determine that a block including a memory cell connected to a word line through which the leakage current is flowing is defective. The word-line leakage detector has a detection voltage generator configured to generate a detection voltage in accordance with the leakage current, a comparator configured to generate a flag signal having output logic that is inverted depending on whether the detection voltage exceeds a predetermined threshold voltage, and an adjuster configured to adjust a current amount by diverting part of the leakage current in accordance with an ambient temperature.