US Patent 11404429 Three-dimensional semiconductor memory devices

Three-dimensional (3D) semiconductor memory devices are provided. A 3D semiconductor memory device includes an electrode structure on a substrate. The electrode structure includes gate electrodes stacked on the substrate. The gate electrodes include electrode pad regions. The 3D semiconductor memory device includes a dummy vertical structure penetrating one of the electrode pad regions. The dummy vertical structure includes a dummy vertical semiconductor pattern and a contact pattern extending from a portion of the dummy vertical semiconductor pattern toward the substrate.