Semiconductor device

A semiconductor device, comprising:

• a substrate;
• a first insulating layer above the substrate;
• a second insulating layer above the first insulating layer;
• a void space between the first insulating layer and the second insulating layer;
• and
• a plurality of contact electrodes extending in a first direction orthogonal to the substrate through the first insulating layer, the void space, and the second insulating layer, wherein
• each of the contact electrodes includes a first end facing the substrate, a second end opposite to the first end, and a first width portion between the first end and the second end, the first width portion having a width in a second direction parallel to the substrate that is greater than a width of the first end in the second direction and a width of the second end in the second direction, the first width portion being within the void space.