A three-dimensional semiconductor device is provided including main separation structures disposed on a substrate, and extending in a first direction, parallel to a surface of the substrate; gate electrodes disposed between the main separation structures; a first secondary separation structure penetrating through the gate electrodes, between the main separation structures, and including a first linear portion and a second linear portion, having end portions opposing each other; and second secondary separation structures disposed between the first secondary separation structure and the main separation structures, and penetrating through the gate electrodes. The second secondary separation structures have end portions opposing each other between the second linear portion and the main separation structures.

To provide a highly reliable semiconductor device exhibiting stable electrical characteristics. To fabricate a highly reliable semiconductor device. Included are an oxide semiconductor stack in which a first to a third oxide semiconductor layers are stacked, a source and a drain electrode layers contacting the oxide semiconductor stack, a gate electrode layer overlapping with the oxide semiconductor layer with a gate insulating layer provided therebetween, and a first and a second oxide insulating layers between which the oxide semiconductor stack is sandwiched. The first to the third oxide semiconductor layers each contain indium, gallium, and zinc. The proportion of indium in the second oxide semiconductor layer is higher than that in each of the first and the third oxide semiconductor layers. The first and the third oxide semiconductor layers are each an amorphous semiconductor film. The second oxide semiconductor layer is a crystalline semiconductor film.

An object is to provide a semiconductor device with a novel structure in which stored data can be held even when power is not supplied and there is no limit on the number of write operations. The semiconductor device includes a first memory cell including a first transistor and a second transistor, a second memory cell including a third transistor and a fourth transistor, and a driver circuit. The first transistor and the second transistor overlap at least partly with each other. The third transistor and the fourth transistor overlap at least partly with each other. The second memory cell is provided over the first memory cell. The first transistor includes a first semiconductor material. The second transistor, the third transistor, and the fourth transistor include a second semiconductor material.

A semiconductor device is described, which includes a first transistor, a second transistor, and a capacitor. The second transistor and the capacitor are provided over the first transistor so as to overlap with a gate of the first transistor. A semiconductor layer of the second transistor and a dielectric layer of the capacitor are directly connected to the gate of the first transistor. The second transistor is a vertical transistor, where its channel direction is perpendicular to an upper surface of a semiconductor layer of the first transistor.

A semiconductor memory device according to one embodiment, includes a first electrode film, a plurality of semiconductor members, and a charge storage member. The first electrode film includes three or more first portions and a second portion connecting the first portions to each other. The first portions extend in a first direction and are arranged along a second direction that intersects with the first direction. The plurality of semiconductor members are arranged along the first direction between the first portions and extending in a third direction. The third direction intersects with a plane containing the first direction and the second direction. The charge storage member is disposed between each of the semiconductor members and each of the first portions. The second portion is disposed between the semiconductor members.

An object of the present invention to provide a highly reliable semiconductor device. Another object is to provide a manufacturing method of a highly reliable semiconductor device. Still another object is to provide a semiconductor device having low power consumption. Yet another object is to provide a manufacturing method of a semiconductor device having low power consumption. Furthermore, another object is to provide a semiconductor device which can be manufactured with high mass productivity. Another object is to provide a manufacturing method of a semiconductor device which can be manufactured with high mass productivity. An impurity remaining in an oxide semiconductor layer is removed so that the oxide semiconductor layer is purified to have an extremely high purity. Specifically, after adding a halogen element into the oxide semiconductor layer, heat treatment is performed to remove an impurity from the oxide semiconductor layer. The halogen element is preferably fluorine.

Stable electric characteristics and high reliability are provided to a miniaturized and integrated semiconductor device including an oxide semiconductor. In a transistor (a semiconductor device) including an oxide semiconductor film, the oxide semiconductor film is provided along a trench (groove) formed in an insulating layer. The trench includes a lower end corner portion having a curved shape with a curvature radius of longer than or equal to 20 nm and shorter than or equal to 60 nm, and the oxide semiconductor film is provided in contact with a bottom surface, the lower end corner portion, and an inner wall surface of the trench. The oxide semiconductor film includes a crystal having a c-axis substantially perpendicular to a surface at least over the lower end corner portion.

Provided is a highly integrated semiconductor device, a semiconductor device with large storage capacity with respect to an area occupied by a capacitor, a semiconductor device capable of high-speed writing, a semiconductor device capable of high-speed reading, a semiconductor device with low power consumption, or a highly reliable semiconductor device. The semiconductor device includes a first transistor, a second transistor, and a capacitor. A conductor penetrates and connects the first transistor, the capacitor, and the second transistor. An insulator is provided on a side surface of the conductor that penetrates the capacitor.

A thin film transistor is deposited over a portion of a metal layer over a substrate. A memory element is coupled to the thin film transistor to provide a first memory cell. A second memory cell is over the first memory. A logic block is coupled to at least the first memory cell.

[Problem] To provide a semiconductor device suitable for miniaturization. To provide a highly reliable semiconductor device. To provide a semiconductor device with improved operating speed.

[Solving Means] A semiconductor device including a memory cell including first to cth (c is a natural number of 2 or more) sub memory cells, wherein: the jth sub memory cell includes a first transistor, a second transistor, and a capacitor; a first semiconductor layer included in the first transistor and a second semiconductor layer included in the second transistor include an oxide semiconductor; one of terminals of the capacitor is electrically connected to a gate electrode included in the second transistor; the gate electrode included in the second transistor is electrically connected to one of a source electrode and a drain electrode which are included in the first transistor; and when j2, the jth sub memory cell is arranged over the j-1th sub memory cell.

[Selected Drawing] FIG. 8