Semiconductor device, method for manufacturing the same, or display device including the same

A semiconductor device comprising:

• a transistor including:
• a first gate electrode;
• a first insulating film over the first gate electrode;
• an oxide semiconductor film over the first insulating film;
• a source electrode over the oxide semiconductor film;
• a drain electrode over the oxide semiconductor film;
• and
• a second insulating film over the oxide semiconductor film, the source electrode, and the drain electrode,
• wherein the source electrode and the drain electrode each include a first conductive film, a second conductive film over and in contact with the first conductive film, and a third conductive film over and in contact with the second conductive film,
• wherein the second conductive film includes copper,
• wherein the first conductive film and the third conductive film each include an oxide conductive film,
• wherein an end portion of the first conductive film is located outward from an end portion of the second conductive film, and
• wherein the third conductive film covers a top surface and a side surface of the second conductive film and is in contact with the first conductive film.