Nonvolatile memory device, system including the same and method for fabricating the same

A nonvolatile memory device, comprising:

• a first substrate;
• a plurality of metal lines stacked on the first substrate in a first direction;
• a channel structure that penetrates the plurality of metal lines;
• a plurality of upper metal layers electrically connected to the plurality of metal lines and the channel structure;
• a plurality of upper bonding metals electrically connected to one or more of the plurality of upper metal layers;
• a first lower interlayer insulation layer and a second lower interlayer insulation layer that are sequentially stacked on the upper bonding metals;
• a plurality of lower bonding metals electrically connected to the upper bonding metals and disposed in the first lower interlayer insulation layer and the second lower interlayer insulation layer;
• and
• a lower metal layer placed between the plurality of lower bonding metals, electrically connected to peripheral circuit elements, and disposed in the second lower interlayer insulation layer,
• wherein an uppermost surface in the first direction of the lower metal layer is lower than a height at which the plurality of lower bonding metals and the plurality of upper bonding metals meet.

A nonvolatile memory system, comprising:

• a main board;
• a nonvolatile memory device disposed on the main board;
• and
• a controller that is electrically connected to the nonvolatile memory device on the main board,
• wherein the nonvolatile memory device includes
• a first substrate,
• a lower metal layer disposed on the first substrate and spaced apart from the first substrate in a first direction, and
• a plurality of lower bonding metals that are spaced apart from each other in a second direction that intersects the first direction,
• wherein an uppermost surface in the first direction of the lower metal layer is lower than an uppermost surface in the first direction of the plurality of lower bonding metals, and
• the lower metal layer is placed between the plurality of lower bonding metals.