Semiconductor device capable of checking deterioration of select transistor and operating method thereof

Abstract

A semiconductor device may include a memory cell array including a memory block including a plurality of memory strings connected between a plurality of bit lines and a common source line, a control circuit that generates a page buffer control signal, a voltage control signal, and a drive address signal, a page buffer group including a plurality of page buffers and configured to form each of the plurality of bit lines to a preset voltage level, and generate a threshold voltage variation result on the basis of a change in the voltage level of each of the plurality of bit lines, a voltage generation circuit that generates a threshold verification voltage and a pass voltage, and a line drive circuit that drives a plurality of select lines to a level of the threshold verification voltage, and drives a plurality of word lines to a level of the pass voltage, during the threshold voltage variation verification.