Semiconductor device and method of manufacturing semiconductor device

A semiconductor device comprising:

• a first connection wiring layer configured to comprise a first insulating layer including a first trench formed on a first surface, and a first electrode provided in the first trench;
• and
• a second connection wiring layer configured to comprise a second insulating layer including a second trench formed on a second surface facing the first surface, and a second electrode provided in the second trench,
• wherein the first connection wiring layer and the second connection wiring layer are bonded such that the first surface and the second surface face each other and the first electrode and the second electrode are in contact with each other,
• wherein the first electrode includes a first barrier metal film provided in the first trench and containing Ti, and a first conductive film provided in the first trench via the first barrier metal film and containing polycrystalline Cu,
• wherein the second electrode includes a second barrier metal film provided in the second trench and containing Ti, and a second conductive film provided in the second trench via the second barrier metal film and containing polycrystalline Cu,
• wherein Ti and O are present on a bonding surface between the first electrode and the second electrode,
• wherein Ti and O are present throughout on the bonding surface,
• wherein the second connection wiring layer of a second substrate includes a first silicon oxide layer, a SiCN film, and a second silicon oxide layer which are stacked in order from a device layer of the second substrate,
• wherein the first silicon oxide layer, the SiCN film, and the second silicon oxide layer constitute a second insulating layer,
• wherein wires are connected to devices provided inside the device layer are provided inside the first silicon oxide layer,
• wherein the first conductive film is a polycrystalline Cu film, and the first barrier metal film is a Ti film, and
• wherein a film containing TiO2 is formed on the bonding surface between the first electrode and the second electrode.