Memory controller and operating method thereof

Abstract

The present disclosure provides a memory controller including a state detector detecting whether the memory device is in an idle state, a program controller, based on detection information that indicates a state of the memory device, selecting neighboring strings that are adjacent to a string that is coupled to a memory cell, among the memory cells, on which a program operation or a read operation was performed before the detecting, selecting monitoring memory cells that are coupled to at least one word line, the memory cells being a part of the neighboring strings, and controlling the memory device to perform a plurality of loops to program the monitoring memory cells, and a bad block selector selecting a memory block with the monitoring memory cells as a bad block based on a rate of increase in threshold voltage of a threshold voltage distribution of the monitoring memory cells.