Semiconductor devices and data storage systems including the same

A semiconductor device, comprising:

• a substrate;
• circuit devices on the substrate;
• lower interconnection lines electrically connected to the circuit devices;
• a peripheral region insulating layer covering the lower interconnection lines;
• a source structure on the peripheral region insulating layer;
• gate electrodes stacked on the source structure and spaced apart from each other in a first direction perpendicular to an upper surface of the source structure;
• channel structures penetrating through the gate electrodes, the channel structures extending in the first direction, and each of the channel structures including a channel layer;
• contact plugs penetrating through the gate electrodes and the source structure, the contact plugs extending in the first direction, and the contact plugs each connected to a portion of the lower interconnection lines;
• and
• spacer layers between the contact plugs and the source structure, and the spacer layers including a material different from a material of the peripheral region insulating layer,
• wherein each of the spacer layers has a first width on an upper surface and each of the spacer layers has a second width greater than the first width on a lower surface.

A data storage system, comprising:

• a semiconductor storage device including
• a substrate, circuit devices on the substrate,
• lower interconnection lines electrically connected to the circuit devices,
• a peripheral region insulating layer covering the lower interconnection lines,
• a plate layer on the peripheral region insulating layer,
• gate electrodes stacked and spaced apart from each other in a first direction perpendicular to an upper surface of the plate layer on the plate layer,
• contact plugs penetrating through the gate electrodes and the plate layer, the contact plugs extending in the first direction, and each of the contact plugs connected to a portion of the lower interconnection lines,
• spacer layers between the contact plugs and the plate layer and the spacer layers including a material different from a material of the peripheral region insulating layer, and
• input/output pads electrically connected to the circuit devices,
• wherein a controller is electrically connected to the semiconductor storage device through the input/output pad and the controller is configured to control the semiconductor storage device, and
• wherein each of the contact plugs has a first width on a level of a lower surface of the plate layer, and each of the contact plugs has a second width greater than the first width on a lower surface of each of the contact plugs.