Semiconductor Energy Laboratory Co., Ltd.

Atsushi Umezaki

Hajime Kimura

Shunpei Yamazaki

Hiroyuki Miyake

Kengo Akimoto

Jun Koyama

Ryo Arasawa

Yasuyuki Arai

Hideaki Shishido

Mai Akiba

Yasunori Yoshida

Makoto Yanagisawa

Takuya Kimishima

Hidekazu Miyairi

Toshiyuki Isa

Shigeki Komori

Satohiro Okamoto

Toshikazu Kondo

A transistor whose channel region includes an oxide semiconductor is used as a pull down transistor. The band gap of the oxide semiconductor is 2.0 eV or more, preferably 2.5 eV or more, more preferably 3.0 eV or more. Thus, hot carrier degradation in the transistor can be suppressed. Accordingly, the circuit size of the semiconductor device including the pull down transistor can be made small. Further, a gate of a pull up transistor is made to be in a floating state by switching of on/off of the transistor whose channel region includes an oxide semiconductor. Note that when the oxide semiconductor is highly purified, the off-state current of the transistor can be 1 aA/μm (1×10A/μm) or less. Therefore, the drive capability of the semiconductor device can be improved.

Display device and electronic device

An object is to provide a display device that performs accurate display. A circuit is formed using a transistor that includes an oxide semiconductor and has a low off-state current. A precharge circuit or an inspection circuit is formed in addition to a pixel circuit. The off-state current is low because the oxide semiconductor is used. Thus, it is not likely that a signal or voltage is leaked in the precharge circuit or the inspection circuit to cause defective display. As a result, a display device that performs accurate display can be provided.

Display device

Provided is a semiconductor device which can operate stably even in the case where a transistor thereof is a depletion transistor. The semiconductor device includes a first transistor for supplying a first potential to a first wiring, a second transistor for supplying a second potential to the first wiring, a third transistor for supplying a third potential at which the first transistor is turned on to a gate of the first transistor and stopping supplying the third potential, a fourth transistor for supplying the second potential to the gate of the first transistor, and a first circuit for generating a second signal obtained by offsetting a first signal. The second signal is input to a gate of the fourth transistor. The potential of a low level of the second signal is lower than the second potential.

Semiconductor device

A semiconductor device where delay or distortion of a signal output to a gate signal line in a selection period is reduced is provided. The semiconductor device includes a gate signal line, a first and second gate driver circuits which output a selection signal and a non-selection signal to the gate signal line, and pixels electrically connected to the gate signal line and supplied with the two signals. In a period during which the gate signal line is selected, both the first and second gate driver circuits output the selection signal to the gate signal line. In a period during which the gate signal line is not selected, one of the first and second gate driver circuits outputs the non-selection signal to the gate signal line, and the other gate driver circuit outputs neither the selection signal nor the non-selection signal to the gate signal line.

The amplitude voltage of a signal input to a level shifter can be increased and then output by the level shifter circuit. Specifically, the amplitude voltage of the signal input to the level shifter can be increased to be output. This decreases the amplitude voltage of a circuit (a shift register circuit, a decoder circuit, or the like) which outputs the signal input to the level shifter. Consequently, power consumption of the circuit can be reduced. Alternatively, a voltage applied to a transistor included in the circuit can be reduced. This can suppress degradation of the transistor or damage to the transistor.

Semiconductor device and electronic appliance

To suppress malfunctions in a shift register circuit. A shift register having a plurality of flip-flop circuits is provided. The flip-flop circuit includes a transistor, a transistor, a transistor, a transistor, and a transistor. When the transistoror the transistoris turned on in a non-selection period, the potential of a node A is set, so that the node A is prevented from entering into a floating state.

Driver circuit, display device, and electronic device

It is an object to provide a display device which can favorably display a image without delayed or distorted signals. The display device includes a first gate driver and a second gate driver. The first gate driver and the second gate driver each include a plurality of flip flop circuits and a plurality of transfer signal generation circuits. Both the flip flop circuit and the transfer signal generation circuit are circuits which output a signal inputted to a first input terminal with a half clock cycle delay. In addition, an output terminal of the transfer signal generation circuit is directly connected to a first input terminal of the flip flop circuit in the next stage. Therefore, delay and distortion of the signal which is inputted from the transfer signal generation circuit to the flip flop circuit can be reduced.

Semiconductor device including gate driver

One of the objects is to improve display quality by reduction in malfunctions of a circuit. In a driver circuit formed using a plurality of pulse output circuits having first to third transistors and first to fourth signal lines, a first clock signal is supplied to the first signal line; a preceding stage signal is supplied to the second signal line; a second clock signal is supplied to the third signal line; an output signal is output from the fourth signal line. Duty ratios of the first clock signal and the second clock signal are different from each other. A period during which the second clock signal is changed from an L-level signal to an H-level signal after the first clock signal is changed from an H-level signal to an L-level signal is longer than a period during which the preceding stage signal is changed from an L-level signal to an H-level signal.

An object is to improve the drive capability of a semiconductor device. The semiconductor device includes a first transistor and a second transistor. A first terminal of the first transistor is electrically connected to a first wiring. A second terminal of the first transistor is electrically connected to a second wiring. A gate of the second transistor is electrically connected to a third wiring. A first terminal of the second transistor is electrically connected to the third wiring. A second terminal of the second transistor is electrically connected to a gate of the first transistor. A channel region is formed using an oxide semiconductor layer in each of the first transistor and the second transistor. The off-state current of each of the first transistor and the second transistor per channel width of 1 μm is 1 aA or less.

Semiconductor device and electronic device

A pixel portion and a driver circuit driving the pixel portion are formed over the same substrate. At least a part of the driver circuit is formed using an inverted staggered thin film transistor in which an oxide semiconductor layer is used and a channel protective layer is provided over the oxide semiconductor layer serving as a channel formation region which is overlapped with the gate electrode. The driver circuit as well as the pixel portion is provided over the same substrate to reduce manufacturing costs.

A driver circuit includes a circuit, a transistor_, and a transistor_. A signal is selectively input from the circuitto a gate of the transistor_and the transistor_, so that the transistor_and the transistor_are controlled to be on or off. The transistor_and the transistor_are turned on or off; thus, the wiringand the wiringbecome conducting or non-conducting.

Liquid crystal display device and electronic device including the same

A semiconductor device or the like with a novel structure that can change the orientation of the display is provided. A semiconductor device or the like with a novel structure, in which a degradation in transistor characteristics can be suppressed, is provided. A semiconductor device or the like with a novel structure, in which operation speed can be increased, is provided. A semiconductor device or the like with a novel structure, in which a dielectric breakdown of a transistor can be suppressed, is provided. The semiconductor device or the like has a circuit configuration capable of switching between a first operation and a second operation by changing the potentials of wirings. By switching between these two operations, the scan direction is easily changed. The semiconductor device is configured to change the scan direction.

Provided is a semiconductor device exemplified by an inverter circuit and a shift register circuit, which is characterized by a reduced number of transistors. The semiconductor device includes a first transistor, a second transistor, and a capacitor. One of a source and a drain of the first transistor is electrically connected to a first wiring, and the other thereof is electrically connected to a second wiring. One of a source and a drain of the second transistor is electrically connected to the first wiring, a gate of the second transistor is electrically connected to a gate of the first transistor, and the other of the source and the drain of the second transistor is electrically connected to one electrode of the capacitor, while the other electrode of the capacitor is electrically connected to a third wiring. The first and second transistors have the same conductivity type.

A first flipflop outputs a first signal synchronized with a first clock signal. In the first transistor, the first clock signal is input to a first terminal and the second signal is output from a second terminal. In the fourth transistor, a first signal is input to a first terminal and a second terminal is electrically connected to a gate of the first transistor. In the sixth transistor, the third signal is input to a first terminal, a second terminal is electrically connected to the gate of the fourth transistor, and the gate of the sixth transistor is electrically connected to the first terminal.

Semiconductor device, display module, and electronic device

It is an object to suppress deterioration of characteristics of a transistor in a driver circuit. A first switch for controlling whether to set a potential state of an output signal by being turned on and off in accordance with the first input signal, and a second switch for controlling whether to set a potential state of an output signal by being turned on and off in accordance with the second input signal are included. A first wiring and a second wiring are brought into electrical continuity by turning on and off of the first switch or the second switch.

Growing community of inventors

Kanagawa, Japan

Atsushi Umezaki