Semiconductor memory device with a switching memory cell in a memory string and operating method thereof

Abstract

A semiconductor device includes a memory string connected between a source line and a bit line. The memory string includes first memory cells stacked along a first channel layer, second memory cells stacked along a second channel layer, and at least one switching memory cell connected between the first memory cells and the second memory cells. A method for operating the semiconductor device includes programming a selected first memory cell among the first memory cells, selecting a second memory cell to be programmed among the second memory cells, applying a program voltage to a word line connected to the selected second memory cell, turning off the switching memory cell such that the first channel layer and the second channel layer are electrically isolated from each other, and applying a pass voltage to word lines connected to unselected memory cells among the first and second memory cells.