A semiconductor device which can efficiently perform reading of a weight coefficient and a product-sum operation is provided. The semiconductor device includes a product-sum operation circuit and a memory device. The product-sum operation circuit is formed using transistors formed on a semiconductor substrate, and a memory cell of the memory device is formed using an OS transistor provided to be stacked above the semiconductor substrate. The semiconductor device includes a plurality of product-sum operation units where the product-sum operation circuit and the memory cell of the memory device are electrically connected to each other. In each of the product-sum operation units, a weight coefficient stored in the memory cell can be read and a product-sum operation can be performed.

A semiconductor device having a large on-state current and high reliability is provided. The semiconductor device includes a first insulator, a first oxide over the first insulator, a second oxide over the first oxide, a third oxide and a fourth oxide over the second oxide, a first conductor over the third oxide, a second conductor over the fourth oxide, a fifth oxide over the second oxide, a second insulator over the fifth oxide, and a third conductor over the second insulator. The fifth oxide is in contact with a top surface of the second oxide, a side surface of the first conductor, a side surface of the second conductor, a side surface of the third oxide, and a side surface of the fourth oxide. The second oxide contains In, an element M, and Zn. The first oxide and the fifth oxide each contain at least one of constituent elements included in the second oxide. The third oxide and the fourth oxide each contain the element M. The third oxide and the fourth oxide include a region where the concentration of the element M is higher than that in the second oxide.

A novel memory device is provided. The memory device includes a plurality of memory cells, and one memory cell includes a first transistor and a second transistor. One of a source and a drain of the first transistor is electrically connected to a gate of the second transistor through a node SN. Data written through the first transistor is retained at the node SN. When an OS transistor is used as the first transistor, formation of a storage capacitor is not needed. A region with a low dielectric constant is provided outside the memory cell, whereby noise from the outside is reduced and stable operation is achieved.

A semiconductor device that can be miniaturized or highly integrated is provided. The semiconductor device includes a first insulator; a first oxide over the first insulator; a second oxide over the first oxide; a first conductor, a second conductor, a third oxide, a fourth oxide, and a second insulator over the second oxide; a third insulator over the first conductor, the second conductor, the third oxide, and the fourth oxide; a fourth insulator over the second insulator; and a third conductor over the fourth insulator. The second insulator is positioned between the first conductor and the second conductor. The third oxide is positioned between the first conductor and the second insulator. The fourth oxide is positioned between the second conductor and the second insulator. The thickness of the third oxide between the first conductor and the second insulator is greater than or equal to 3 nm and less than or equal to 8 nm. The thickness of the fourth oxide between the second conductor and the second insulator is greater than or equal to 3 nm and less than or equal to 8 nm.

A semiconductor device includes a CPU and an accelerator that includes a first memory circuit, a driver circuit, and a product-sum operation circuit. The first memory circuit includes a first data retention portion, a second data retention portion, and a data reading portion. The first data retention portion, the second data retention portion, and the data reading portion each include a first transistor. The first transistor contains a metal oxide in a channel formation region. First data stored in the first data retention portion and second data stored in the second data retention portion are each weight data input to the product-sum operation circuit. The product-sum operation circuit has a function of performing product-sum operation of the weight data and input data input through the driver circuit. The product-sum operation circuit and the driver circuit each include a second transistor. The second transistor contains silicon in a channel formation region. The first transistor and the second transistor are stacked.

A highly reliable memory device is provided. On a side surface of a first conductor extending in a first direction, a first insulator, a first semiconductor, a second insulator, a second semiconductor, and a third insulator are provided in this order when seen from the first conductor side. The first conductor is provided with a first region overlapping with a second conductor with the first insulator, the first semiconductor, the second insulator, the second semiconductor, and the third insulator provided therebetween, and a second region overlapping with a third conductor with the first insulator, the first semiconductor, the second insulator, the second semiconductor, and the third insulator provided therebetween. In the second region, a fourth conductor is provided between the first insulator and the first semiconductor.

A highly reliable memory device is provided. On a side surface of a first conductor extending in a first direction, a first insulator, a first semiconductor, a second insulator, a second semiconductor, and a third insulator are provided in this order when seen from the first conductor side. A first region overlapping with a second conductor with the first insulator, the first semiconductor, the second insulator, the second semiconductor, and the third insulator therebetween, and a second region overlapping with a third conductor with the first insulator, the first semiconductor, the second insulator, the second semiconductor, and the third insulator therebetween are provided in the first conductor. In the second region, a fourth conductor is provided between the first insulator and the first semiconductor.

A manufacturing method of a semiconductor device in which the threshold is adjusted to an appropriate value is provided. The semiconductor device includes a semiconductor, a source or drain electrode electrically connected to the semiconductor, a first gate electrode and a second gate electrode between which the semiconductor is sandwiched, an electron trap layer between the first gate electrode and the semiconductor, and a gate insulating layer between the second gate electrode and the semiconductor. By keeping a potential of the first gate electrode higher than a potential of the source or drain electrode for 1 second or more while heating, electrons are trapped in the electron trap layer. Consequently, threshold is increased and Icut is reduced.

A semiconductor device includes a transistor including, a first to fifth insulator, a first to third oxide, a first to third conductor. An opening reaching the second oxide is provided in the fourth insulator and the fifth insulator. The third oxide, the third insulator, and the third conductor are arranged sequentially from the inner wall side of the opening so as to fill the opening. In the channel length direction of the transistor, at least part of the fourth insulator in a region where the fourth insulator and the second oxide do not overlap with each other is in contact with the first insulator. In the channel width direction of the transistor, at least part of the third oxide in a region where the third oxide and the second oxide do not overlap with each other is in contact with the first insulator.

Provision of a novel semiconductor device. The semiconductor device includes a first control circuit including a first transistor using a silicon substrate for a channel; a second control circuit provided over the first control circuit, which includes a second transistor using a metal oxide for a channel; a memory circuit provided over the second control circuit, which includes a third transistor using a metal oxide for a channel; and a global bit line and an inverted global bit line that have a function of transmitting a signal between the first control circuit and the second control circuit. The first control circuit includes a sense amplifier circuit including an input terminal and an inverted input terminal. In a first period for reading data from the memory circuit to the first control circuit, the second control circuit controls whether the global bit line and the inverted global bit line from which electric charge is discharged are charged or not in accordance with the data read from the memory circuit.