Abstract: A semiconductor storage device includes a first oxide semiconductor layer that extends in a first direction; a second oxide semiconductor layer that extends in the first direction and is adjacent to the first oxide semiconductor layer in a second direction intersecting to the first direction; first wiring that extends in a third direction intersecting to the first direction and overlaps with the first oxide semiconductor layer in the third direction; second wiring that extends in the third direction and overlaps with the second oxide semiconductor layer in the third direction; a first insulating film that is provided between the first wiring and the first oxide semiconductor layer; a second insulating film that is provided between the second wiring and the second oxide semiconductor layer; a first conductor that is provided on the first oxide semiconductor layer; a second conductor that is provided on the second oxide semiconductor layer; and an insulating layer that has a gap between the first conductor and

Abstract: A semiconductor device includes: an oxide semiconductor layer extending in a first direction; a gate electrode overlapping the oxide semiconductor layer in a second direction intersecting the first direction; a gate insulating film provided between the gate electrode and the oxide semiconductor layer; a first conductive layer provided on the oxide semiconductor layer in the first direction and containing a conductive oxide; a second conductive layer provided on the first conductive layer in the first direction and containing a metal element; a first protective film in contact with a side surface of the second conductive layer; and a second protective film in contact with at least a part of a side surface or an upper surface of the first conductive layer. The first protective film and the second protective film each contain a material having an oxygen diffusion coefficient smaller than that of the second conductive layer.