Abstract: A liquid crystal display device includes: a driver circuit portion; a pixel portion; a signal generation circuit for generating a control signal for driving the driver circuit portion and an image signal which is supplied to the pixel portion; a memory circuit; a comparison circuit for detecting a difference of image signals for a series of frame periods among image signals stored for respective frame periods in the memory circuit; a selection circuit which selects and outputs the image signals for the series of frame periods when the difference is detected in the comparison circuit; and a display control circuit which supplies the control signal and the image signals output from the selection circuit, to the driver circuit portion when the difference is detected in the comparison circuit, and stops supplying the control signal to the driver circuit portion when the difference is not detected in the comparison circuit.

Abstract: It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided.

Abstract: A semiconductor device with improved electrical characteristics is provided. A semiconductor device with improved field effect mobility is provided. A semiconductor device in which the field-effect mobility is not lowered even at high temperatures is provided. A semiconductor device which can be formed at low temperatures is provided. A semiconductor device with improved productivity can be provided. In the semiconductor device, there is a range of a gate voltage where the field-effect mobility increases as the temperature increases within a range of the gate voltage from 0 V to 10 V. For example, such a range of a gate voltage exists at temperatures ranging from a room temperature (25° C.) to 120° C. In the semiconductor device, the off-state current is kept extremely low (lower than or equal to the detection limit of a measurement device) within the above temperature range.

Abstract: A display device including a pixel having a memory. The pixel includes at least a display element, a capacitor, an inverter, and a switch. The switch is controlled with a signal held in the capacitor and a signal output from the inverter so that voltage is supplied to the display element. The inverter and the switch can be constituted by transistors with the same polarity. A semiconductor layer included in the pixel may be formed using a light-transmitting material. Moreover, a gate electrode, a drain electrode, and a capacitor electrode may be formed using a light-transmitting conductive layer. The pixel is formed using a light-transmitting material in such a manner, whereby the display device can be a transmissive display device while including a pixel having a memory.

Abstract: The on-state characteristics of a transistor are improved and thus, a semiconductor device capable of high-speed response and high-speed operation is provided. A highly reliable semiconductor device showing stable electric characteristics is made. The semiconductor device includes a transistor including a first oxide layer; an oxide semiconductor layer over the first oxide layer; a source electrode layer and a drain electrode layer in contact with the oxide semiconductor layer; a second oxide layer over the oxide semiconductor layer; a gate insulating layer over the second oxide layer; and a gate electrode layer over the gate insulating layer. An end portion of the second oxide layer and an end portion of the gate insulating layer overlap with the source electrode layer and the drain electrode layer.

Abstract: A metal oxide film including a crystal part and having highly stable physical properties is provided. The size of the crystal part is less than or equal to 10 nm, which allows the observation of circumferentially arranged spots in a nanobeam electron diffraction pattern of the cross section of the metal oxide film when the measurement area is greater than or equal to 5 nm? and less than or equal to 10 nm?.

Abstract: In a transistor including an oxide semiconductor, a variation in electrical characteristics is suppressed and reliability is improved. A semiconductor device includes a transistor. The transistor includes a first gate electrode, a first insulating film over the first gate electrode, an oxide semiconductor film over the first insulating film, a second insulating film over the oxide semiconductor film, a second gate electrode over the second insulating film, and a third insulating film over the oxide semiconductor film and the second gate electrode. The oxide semiconductor film includes a channel region overlapping with the second gate electrode, a source region in contact with the third insulating film, and a drain region in contact with the third insulating film. The first gate electrode and the second gate electrode are electrically connected to each other.

Abstract: An object is to obtain a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range, using a thin film transistor in which an oxide semiconductor layer is used. An analog circuit is formed with the use of a thin film transistor including an oxide semiconductor which has a function as a channel formation layer, has a hydrogen concentration of 5×1019 atoms/cm3 or lower, and substantially functions as an insulator in the state where no electric field is generated. Thus, a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range can be obtained.

Abstract: An oxide semiconductor film which has more stable electric conductivity is provided. The oxide semiconductor film comprises a crystalline region. The oxide semiconductor film has a first peak of electron diffraction intensity with a full width at half maximum of greater than or equal to 0.4 nm?1 and less than or equal to 0.7 nm?1 in a region where a magnitude of a scattering vector is greater than or equal to 3.3 nm?1 and less than or equal to 4.1 nm?1. The oxide semiconductor film has a second peak of electron diffraction intensity with a full width at half maximum of greater than or equal to 0.45 nm?1 and less than or equal to 1.4 nm?1 in a region where a magnitude of a scattering vector is greater than or equal to 5.5 nm?1 and less than or equal to 7.1 nm?1.

Abstract: To reduce a leakage current of a transistor so that malfunction of a logic circuit can be suppressed. The logic circuit includes a transistor which includes an oxide semiconductor layer having a function of a channel formation layer and in which an off current is 1×10?13A or less per micrometer in channel width. A first signal, a second signal, and a third signal that is a clock signal are input as input signals. A fourth signal and a fifth signal whose voltage states are set in accordance with the first to third signals which have been input are output as output signals.

Abstract: An object is to reduce leakage current and parasitic capacitance of a transistor used for an LSI, a CPU, or a memory. A semiconductor integrated circuit included in an LSI, a CPU, or a memory is manufactured using the transistor which is formed using an oxide semiconductor which is an intrinsic or substantially intrinsic semiconductor obtained by removal of impurities which serve as electron donors (donors) from the oxide semiconductor and has larger energy gap than a silicon semiconductor, and is formed over a semiconductor substrate. With the transistor which is formed over the semiconductor substrate and includes the highly purified oxide semiconductor layer with sufficiently reduced hydrogen concentration, a semiconductor device whose power consumption due to leakage current is low can be realized.

Abstract: A method comprising a step of forming an oxide semiconductor film over a substrate by a sputtering method while heating the substrate at a temperature of higher than 200° C. and lower than or equal to 400° C. is provided. The oxide semiconductor film comprises a crystalline region and is in a non-single-crystal state. The step of forming the oxide semiconductor film is performed by using a sputtering target comprising indium, gallium, zinc and oxygen and a sputtering gas comprising at least one of a rare gas and oxygen.

Abstract: An object is to reduce leakage current and parasitic capacitance of a transistor used for an LSI, a CPU, or a memory. A semiconductor integrated circuit such as an LSI, a CPU, or a memory is manufactured using a thin film transistor in which a channel formation region is formed using an oxide semiconductor which becomes an intrinsic or substantially intrinsic semiconductor by removing impurities which serve as electron donors (donors) from the oxide semiconductor and has larger energy gap than that of a silicon semiconductor. With use of a thin film transistor using a highly purified oxide semiconductor layer with sufficiently reduced hydrogen concentration, a semiconductor device with low power consumption due to leakage current can be realized.

Abstract: A liquid crystal display device includes: a driver circuit portion; a pixel portion; a signal generation circuit for generating a control signal for driving the driver circuit portion and an image signal which is supplied to the pixel portion; a memory circuit; a comparison circuit for detecting a difference of image signals for a series of frame periods among image signals stored for respective frame periods in the memory circuit; a selection circuit which selects and outputs the image signals for the series of frame periods when the difference is detected in the comparison circuit; and a display control circuit which supplies the control signal and the image signals output from the selection circuit, to the driver circuit portion when the difference is detected in the comparison circuit, and stops supplying the control signal to the driver circuit portion when the difference is not detected in the comparison circuit.

Abstract: A change in electrical characteristics is suppressed and reliability in a semiconductor device using a transistor including an oxide semiconductor is improved. One feature resides in forming an oxide semiconductor film over an oxygen-introduced insulating film, and then forming the source and drain electrodes with an antioxidant film thereunder. Here, in the antioxidant film, the width of a region overlapping with the source and drain electrodes is longer than the width of a region not overlapping with them. The transistor formed as such has less defects in the channel region, which will improve reliability of the semiconductor device.

Abstract: A semiconductor device with improved electrical characteristics is provided. A semiconductor device with improved field effect mobility is provided. A semiconductor device in which the field-effect mobility is not lowered even at high temperatures is provided. A semiconductor device which can be formed at low temperatures is provided. A semiconductor device with improved productivity can be provided. In the semiconductor device, there is a range of a gate voltage where the field-effect mobility increases as the temperature increases within a range of the gate voltage from 0 V to 10 V. For example, such a range of a gate voltage exists at temperatures ranging from a room temperature (25° C.) to 120° C. In the semiconductor device, the off-state current is kept extremely low (lower than or equal to the detection limit of a measurement device) within the above temperature range.

Abstract: Exemplary semiconductor devices include eight transistors and two capacitors interconnected in specific configurations. A display device may include a driver circuit having such a semiconductor device. An electronic device may also include such a semiconductor device and an input unit, LED lamp or speaker.

Abstract: A metal oxide film including a crystal part and having highly stable physical properties is provided. The size of the crystal part is less than or equal to 10 nm, which allows the observation of circumferentially arranged spots in a nanobeam electron diffraction pattern of the cross section of the metal oxide film when the measurement area is greater than or equal to 5 nm? and less than or equal to 10 n?.

Abstract: Provided is a highly reliable semiconductor device, a semiconductor device with a reduced circuit area, a memory element having favorable characteristics, a highly reliable memory element, or a memory element with increased storage capacity per unit volume. A semiconductor device includes a capacitor and a switching element. The capacitor includes a first electrode, a second electrode, and a dielectric. The dielectric is positioned between the first electrode and the second electrode. The switching element includes a first terminal and a second terminal. The first terminal is electrically connected to the first electrode. The following steps are sequentially performed: a first step of turning on the switching element in a first period, a second step of turning off the switching element in a second period, and a third step of turning on the switching element in a third period.

Abstract: In a liquid crystal display device including a plurality of pixels in a display portion and configured to performed display in a plurality of frame periods, each of the frame periods includes a writing period and a holding period, and after an image signal is input to each of the plurality of pixels in the writing period, a transistor included in each of the plurality of pixels is turned off and the image signal is held for at least 30 seconds in the holding period. The pixel includes a semiconductor layer including an oxide semiconductor layer, and the oxide semiconductor layer has a carrier concentration of less than 1×1014/cm3.