Semiconductor device, display device, display module, and electronic device

A semiconductor device comprising:

• a first functional layer;
• a second functional layer;
• and
• a first conductive layer,
• wherein the second functional layer overlaps with the first functional layer,
• wherein the second functional layer comprises a functional element,
• wherein the functional element comprises a first electrode,
• wherein the first functional layer comprises a first layer, a spacer, and a transistor,
• wherein the first layer is sandwiched between the second functional layer and the spacer,
• wherein the first layer comprises a first opening portion,
• wherein the first layer has an insulating property,
• wherein the spacer comprises a first plane, a second plane, a third plane, and a second opening portion,
• wherein the first plane, the second plane, and the third plane each have an insulating property,
• wherein the second plane faces the first plane,
• wherein the second plane is positioned closer to the first layer than the first plane is,
• wherein the third plane connects the first plane and the second plane to each other,
• wherein the third plane is positioned at a side surface of the second opening portion,
• wherein the transistor comprises a second electrode, a third electrode, a fourth electrode, a semiconductor layer, and an insulating layer,
• wherein the second electrode comprises a region in contact with the first plane and a region overlapping with the second opening portion,
• wherein the third electrode comprises a region in contact with the second plane, a third opening portion, and a fourth plane,
• wherein the fourth plane is positioned at a side surface of the third opening portion,
• wherein the third opening portion overlaps with the second opening portion,
• wherein the fourth electrode comprises a region facing the third plane,
• wherein the insulating layer comprises a region sandwiched between the third plane and the fourth electrode,
• wherein the semiconductor layer comprises a region sandwiched between the third plane and the insulating layer,
• wherein the semiconductor layer is in contact with the second electrode in the second opening portion,
• wherein the semiconductor layer is in contact with the third electrode at the fourth plane, and
• wherein the first conductive layer electrically connects the third electrode and the first electrode to each other through the first opening portion.