Semiconductor device and semiconductor memory device

A semiconductor device comprising:

• an oxide semiconductor layer;
• a gate electrode;
• a gate insulating layer provided between the oxide semiconductor layer and the gate electrode;
• a first electrode electrically connected to the oxide semiconductor layer at a first position of the oxide semiconductor layer;
• a second electrode electrically connected to the oxide semiconductor layer at a second position of the oxide semiconductor layer disposed in a first direction with respect to the first position;
• a first conductive layer provided at at least one position between the oxide semiconductor layer and the first electrode or between the oxide semiconductor layer and the second electrode, the first conductive layer containing a first metal element, a first element different from the first metal element, and at least one element of oxygen (O) or nitrogen (N);
• and
• a second conductive layer provided between the oxide semiconductor layer and the first conductive layer, the second conductive layer containing oxygen (O) and a second element different from both of the first metal element and the first element,
• wherein a third position of the oxide semiconductor layer facing the gate electrode is disposed between the first position and the second position in the first direction,
• wherein a crystal grain size of the first conductive layer is smaller than a crystal grain size of the second conductive layer.

A semiconductor memory device comprising:

• a first wire extending in a first direction;
• a second wire extending in a second direction intersecting the first direction;
• and
• a memory cell,
• wherein the memory cell includes
• an oxide semiconductor layer electrically connected to the first wire, the oxide semiconductor layer being surrounded by a part of the second wire,
• a gate insulating layer provided between the oxide semiconductor layer and the part of the second wire,
• a capacitor electrically connected to the oxide semiconductor layer,
• a first conductive layer provided at at least one position between the oxide semiconductor layer and the first wire or between the oxide semiconductor layer and the capacitor, the first conductive layer containing a first metal element, a first element different from the first metal element, and oxygen (O), and
• a second conductive layer provided between the oxide semiconductor layer and the first conductive layer, the second conductive layer containing oxygen (O) and a second element different from both of the first metal element and the first element.