Abstract: A semiconductor device with a high on-state current and high operating speed is provided. The semiconductor device includes a transistor and a first circuit. The transistor includes a first gate and a second gate, and the first gate and the second gate include a region where they overlap each other with a semiconductor layer therebetween. The first circuit includes a temperature sensor and a voltage control circuit. The temperature sensor has a function of obtaining temperature information and outputting the temperature information to the voltage control circuit. The voltage control circuit has a function of converting the temperature information into a control voltage. The first circuit applies the control voltage to the second gate.

Abstract: A novel memory device is provided. The memory device including a plurality of memory cells arranged in a matrix, and each of the memory cells includes a transistor and a capacitor. The transistor includes a first gate and a second gate, which include a region where they overlap with each other with a semiconductor layer therebetween. The memory device has a function of operating in a “writing mode”, a “reading mode”, a “refresh mode”, and an “NV mode”. In the “refresh mode”, data retained in the memory cell is read, and then the read data is written to the memory cell again for first time. In the “NV mode”, data retained in the memory cell is read, the read data is written to the memory cell again for second time, and then a potential at which the transistor is turned off is supplied to the second gate. The “NV mode” operation enables data to be stored for a long time even when power supply to the memory cell is stopped. The memory cell can store multilevel data.

Abstract: To reduce the area of a memory cell having a backup function. A storage device includes a cell array, and a row circuit and a column circuit that drive the cell array. The cell array includes a first power supply line, a second power supply line, a word line, a pair of bit lines, a memory cell, and a backup circuit. The cell array is located in a power domain where power gating can be performed. In the power gating sequence of the cell array, data in the memory cell is backed up to the backup circuit. The backup circuit is stacked over a region where the memory cell is formed. A plurality of wiring layers are provided between the backup circuit and the memory cell. The first power supply line, the second power supply line, the word line, and the pair of bit lines are located in different wiring layers.

Abstract: An object is to provide a semiconductor device with a novel structure. The semiconductor device includes a first wiring; a second wiring; a third wiring; a fourth wiring; a first transistor having a first gate electrode, a first source electrode, and a first drain electrode; and a second transistor having a second gate electrode, a second source electrode, and a second drain electrode. The first transistor is provided in a substrate including a semiconductor material. The second transistor includes an oxide semiconductor layer.

Abstract: A novel storage device and a novel semiconductor device are provided. In the storage device, a cell array including a plurality of memory cells is stacked above a control circuit, and the cell array operates separately in a plurality of blocks. Furthermore, a plurality of electrodes are included between the control circuit and the cell array. The electrode is provided for a corresponding block to overlap with the block, and a potential of the electrode can be changed for each block. The electrode has a function of aback gate of a transistor included in the memory cell, and a potential of the electrode is changed for each block, whereby the electrical characteristics of the transistor included in the memory cell can be changed. Moreover, the electrode can reduce noise caused in the control circuit.

Abstract: A semiconductor device that is suitable for miniaturization and higher density is provided. A semiconductor device includes a first transistor over a semiconductor substrate, a second transistor including an oxide semiconductor over the first transistor, and a capacitor over the second transistor. The capacitor includes a first conductor, a second conductor, and an insulator. The second conductor covers a side surface of the first conductor with an insulator provided therebetween.

Abstract: Provided is a structure which is capable of central control of an electric device and a sensor device and a structure which can reduce power consumption of an electric device and a sensor device. A central control system includes at least a central control device, an output unit, and an electric device or a sensor device. The central control device performs arithmetic processing on information transmitted from the electric device or the sensor device and makes the output unit output information obtained by the arithmetic processing. It is possible to know the state of the electric device or the sensor device even apart from the electric device or the sensor device. The electric device or the sensor device includes a transistor which includes an activation layer using a semiconductor with the band gap wider than that of single crystal silicon.

Abstract: An object is to provide a semiconductor device with a novel structure. The semiconductor device includes a first wiring; a second wiring; a third wiring; a fourth wiring; a first transistor having a first gate electrode, a first source electrode, and a first drain electrode; and a second transistor having a second gate electrode, a second source electrode, and a second drain electrode. The first transistor is provided in a substrate including a semiconductor material. The second transistor includes an oxide semiconductor layer.

Abstract: It is an object to provide a memory device whose power consumption can be suppressed and a semiconductor device including the memory device. As a switching element for holding electric charge accumulated in a transistor which functions as a memory element, a transistor including an oxide semiconductor film as an active layer is provided for each memory cell in the memory device. The transistor which is used as a memory element has a first gate electrode, a second gate electrode, a semiconductor film located between the first gate electrode and the second gate electrode, a first insulating film located between the first gate electrode and the semiconductor film, a second insulating film located between the second gate electrode and the semiconductor film, and a source electrode and a drain electrode in contact with the semiconductor film.

Abstract: An imaging device which has a stacked-layer structure and can be manufactured easily is provided. The imaging device includes a signal processing circuit, a memory device, and an image sensor. The imaging device has a stacked-layer structure in which the memory device is provided above the signal processing circuit, and the image sensor is provided above the memory device. The signal processing circuit includes a transistor formed on a first semiconductor substrate, the memory device includes a transistor including a metal oxide in a channel formation region, and the image sensor includes a transistor formed on a second semiconductor substrate.

Abstract: To provide a novel semiconductor device.

Abstract: A semiconductor device whose operating speed is increased is provided. The semiconductor device includes a write word line, a read word line, a write bit line, a read bit line, a first wiring, and a memory cell. The memory cell includes three transistors of a single conductivity type and a capacitor. Gates of the three transistors are electrically connected to the write word line, a first terminal of the capacitor, and the read word line, respectively. A second terminal of the capacitor is electrically connected to the read bit line. A source and a drain of one transistor are electrically connected to the write bit line and the gate of another transistor, respectively. Two of the three transistors are electrically connected in series between the read bit line and the first wiring. A channel formation region of each of the three transistors includes, for example, a metal oxide layer.

Abstract: Disclosed is a semiconductor device including: an insulating layer; a source electrode and a drain electrode embedded in the insulating layer; an oxide semiconductor layer in contact and over the insulating layer, the source electrode, and the drain electrode; a gate insulating layer over and covering the oxide semiconductor layer; and a gate electrode over the gate insulating layer, where the upper surfaces of the insulating layer, the source electrode, and the drain electrode exist coplanarly. The upper surface of the insulating layer, which is in contact with the oxide semiconductor layer, has a root-mean-square (RMS) roughness of 1 nm or less, and the difference in height between the upper surface of the insulating layer and the upper surface of the source electrode or the drain electrode is less than 5 nm. This structure contributes to the suppression of defects of the semiconductor device and enables their miniaturization.

Abstract: A semiconductor device that is suitable for miniaturization and higher density is provided. A semiconductor device includes a first transistor over a semiconductor substrate, a second transistor including an oxide semiconductor over the first transistor, and a capacitor over the second transistor. The capacitor includes a first conductor, a second conductor, and an insulator. The second conductor covers a side surface of the first conductor with an insulator provided therebetween.

Abstract: Provided is a semiconductor device that can directly compare two negative potentials. The semiconductor device includes a first to a third transistor and a load and is configured to compare a first negative potential and a second negative potential. The first negative potential and the second negative potential are input to a gate of the first transistor and a gate of the second transistor, respectively. Each drain of the first transistor and the second transistor is electrically connected to the load. The third transistor serves as a current source. The first transistor and the second transistor each include a backgate. A positive potential is input to the backgates.

Abstract: A memory device in which bit line parasitic capacitance is reduced is provided. The memory device includes a sense amplifier electrically connected to a bit line and a memory cell array stacked over the sense amplifier. The memory cell array includes a plurality of memory cells. The plurality of memory cells are each electrically connected to a bit line. A portion for leading the bit lines is not provided in the memory cell array. Thus, the bit line can be shortened and the bit line parasitic capacitance is reduced.

Abstract: A semiconductor device with a large storage capacity per unit area is provided. The semiconductor device includes a first insulator including a first opening, a first conductor that is over the first insulator and includes a second opening, a second insulator that is over the first insulator and includes a third opening, and an oxide penetrating the first opening, the second opening, and the third opening. The oxide includes a first region at least in the first opening, a second region at least in the second opening, and a third region at least in the third opening. The resistances of the first region and the third region are lower than the resistance of the second region.

Abstract: An object of one embodiment of the present invention is to provide a semiconductor device with a novel structure in which stored data can be stored even when power is not supplied in a data storing time and there is no limitation on the number of times of writing. The semiconductor device includes a first transistor which includes a first channel formation region using a semiconductor material other than an oxide semiconductor, a second transistor which includes a second channel formation region using an oxide semiconductor material, and a capacitor. One of a second source electrode and a second drain electrode of the second transistor is electrically connected to one electrode of the capacitor.

Abstract: Provided is a comparison circuit to which a negative voltage to be compared can be input directly. The comparison circuit includes a first input terminal, a second input terminal, a first output terminal, and a differential pair. The comparison circuit compares a negative voltage and a negative reference voltage and outputs a first output voltage from the first output terminal in response to the comparison result. The negative voltage is input to the first input terminal. A positive reference voltage is input to the second input terminal. The positive reference voltage is determined so that comparison is performed. The differential pair includes a first n-channel transistor and a second n-channel transistor each having a gate and a backgate. The first input terminal is electrically connected to the backgate of the first n-channel transistor. The second input terminal is electrically connected to the gate of the second n-channel transistor.

Abstract: A semiconductor device enabling high integration is provided. The semiconductor device includes a plug, two capacitors, and two transistors sharing one oxide semiconductor. Each of the transistors includes a stacked-layer structure of a gate insulator and a gate electrode over the oxide semiconductor and an insulator in contact with a side surface of the gate electrode. An opening between the two gate electrodes exposes the insulators in contact with the side surfaces of the gate electrodes, and the plug is in the opening. The capacitor is directly provided over the oxide semiconductor. The side surface area of the capacitor is larger than the projected area of the capacitor.