Semiconductor device

A semiconductor device comprising:

• a first chip including:
• a substrate,
• a first interconnect layer provided above the substrate,
• a first pad provided above the first interconnect layer;
• and
• a first plug extending in a first direction crossing a surface of the substrate and connecting the first interconnect layer and the first pad;
• and
• a second chip including:
• a second interconnect layer,
• a second pad provided under the second interconnect layer,
• a second plug extending in the first direction and connecting the second interconnect layer and the second pad,
• a memory cell array electrically connected to the second interconnect layer, and
• a bit line provided between the second interconnect layer and the memory cell array in the first direction, wherein
• the first plug shifts with respect to the second plug in a plane crossing the first direction,
• the first pad includes a first portion overlapping with the first plug in the first direction, and a second portion other than the first portion,
• the second pad includes a third portion overlapping with the second plug in the first direction, and a fourth portion other than the third portion,
• the first portion of the first pad is all bonded with the second pad,
• the third portion of the second pad is all bonded with the first pad, and
• the second portion of the first pad surrounds the first portion of the first pad and has a closed ring-shape, when viewed from the first direction, and
• a cavity is provided between the second portion of the first pad and a part of the second pad.