Three-dimensional semiconductor memory device and method of detecting electrical failure thereof

Abstract

Disclosed are three-dimensional semiconductor memory devices and methods of detecting electrical failure thereof. The three-dimensional semiconductor memory device includes a substrate with a first conductivity including a cell array region and an extension region having different threshold voltages from each other, a stack structure on the substrate and including stacked electrodes, an electrical vertical channel penetrating the stack structure on the cell array region, and a dummy vertical channel penetrating the stack structure on the extension region. The substrate comprises a pocket well having the first conductivity and provided with the stack structure thereon, and a deep well surrounding the pocket well and having a second conductivity opposite to the first conductivity.