Semiconductor device and electronic system including the same

Abstract

A semiconductor device may include a first substrate structure including a substrate, circuit elements on the substrate, and first bonding layers on the circuit elements, and a second substrate structure on the first substrate structure. The second substrate structure may include a plate layer, an intermediate insulating layer below the plate layer and including silicon nitride, gate electrodes below the intermediate insulating layer and stacked to be spaced apart from each other in a vertical direction, a channel structure in a channel hole passing through the intermediate insulating layer and the gate electrodes and including a semiconductor layer, and second bonding layers connected to the first bonding layers. The channel hole may have a first width in a first portion passing through the gate electrodes and a second width, wider than the first width, in a second portion passing through the intermediate insulating layer.