Semiconductor devices having separation regions in gate electrode layers, and data storage systems including the same

A semiconductor device comprising:

• a substrate;
• gate electrode layers on the substrate and spaced apart from each other in a first direction that is perpendicular to an upper surface of the substrate;
• interlayer insulating layers alternately stacked with the gate electrode layers on the substrate in the first direction;
• channel structures extending through the gate electrode layers and the interlayer insulating layers, extending in the first direction, and including respective channel layers;
• a cell region insulating layer on the gate electrode layers and the channel structures;
• and
• separation regions extending through the gate electrode layers and the cell region insulating layer and extending in the first direction and in a second direction that is parallel to the upper surface of the substrate,
• wherein each of the separation regions comprises a region extending through the cell region insulating layer and further comprises first and second surfaces that are parallel to upper surface of the substrate and are in the region, and
• wherein the first surface is between the upper surface of the substrate and the second surface.

A data storage system comprising:

• a semiconductor storage device including a substrate, circuit elements on a first side of the substrate, gate electrode layers on the substrate and spaced apart from each other in a first direction that is perpendicular to an upper surface of the substrate, interlayer insulating layers alternately stacked with the gate electrode layers on the substrate in the first direction, channel structures extending through the gate electrode layers and the interlayer insulating layers, extending in the first direction, and including respective channel layers, a cell region insulating layer on the gate electrode layers and the channel structures, separation regions extending through the gate electrode layers and the interlayer insulating layers, and extending in the first direction and in a second direction that is parallel to the upper surface of the substrate, and an input/output pad electrically connected to one of the circuit elements;
• and
• a controller electrically connected to the semiconductor storage device through the input/output pad and configured to control the semiconductor storage device,
• wherein each of the separation regions comprises a region extending through the cell region insulating layer and further comprises first and second surfaces that are parallel to the upper surface of the substrate and are in the region, and
• wherein the first surface is between the upper surface of the substrate and the second surface.