Abstract: A semiconductor device capable of obtaining the threshold voltage of a transistor is provided. The semiconductor device includes a first transistor, a first capacitor, a first output terminal, a first switch, and a second switch. A gate and a source of the first transistor are electrically connected to each other. A first terminal of the first capacitor is electrically connected to the source. A second terminal and the first output terminal of the first capacitor are electrically connected to a back gate of the first transistor. The first switch controls input of a first voltage to the back gate. A second voltage is input to a drain of the first transistor. The second switch controls input of a third voltage to the source.

Abstract: To improve field-effect mobility and reliability in a transistor including an oxide semiconductor film. A semiconductor device includes a transistor including an oxide semiconductor film. The transistor includes a region where the maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 40 and smaller than 150; a region where the threshold voltage is higher than or equal to minus 1 V and lower than or equal to 1 V; and a region where the S value is smaller than 0.3 V/decade.

Abstract: To improve field-effect mobility and reliability in a transistor including an oxide semiconductor film. A semiconductor device includes a transistor including an oxide semiconductor film. The transistor includes a region where the maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 40 and smaller than 150; a region where the threshold voltage is higher than or equal to minus 1 V and lower than or equal to 1 V; and a region where the S value is smaller than 0.3 V/decade.

Abstract: A semiconductor device capable of obtaining the threshold voltage of a transistor is provided. The semiconductor device includes a first transistor, a first capacitor, a first output terminal, a first switch, and a second switch. A gate and a source of the first transistor are electrically connected to each other. A first terminal of the first capacitor is electrically connected to the source. A second terminal and the first output terminal of the first capacitor are electrically connected to a back gate of the first transistor. The first switch controls input of a first voltage to the back gate. A second voltage is input to a drain of the first transistor. The second switch controls input of a third voltage to the source.

Abstract: To improve field-effect mobility and reliability in a transistor including an oxide semiconductor film. A semiconductor device includes a transistor including an oxide semiconductor film. The transistor includes a region where the maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 40 and smaller than 150; a region where the threshold voltage is higher than or equal to minus 1 V and lower than or equal to 1 V; and a region where the S value is smaller than 0.3 V/decade.

Abstract: To improve field-effect mobility and reliability in a transistor including an oxide semiconductor film. A semiconductor device includes a transistor including an oxide semiconductor film. The transistor includes a region where the maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 40 and smaller than 150; a region where the threshold voltage is higher than or equal to minus 1 V and lower than or equal to 1 V; and a region where the S value is smaller than 0.3 V/decade.

Abstract: A semiconductor device capable of obtaining the threshold voltage of a transistor is provided. The semiconductor device includes a first transistor, a first capacitor, a first output terminal, a first switch, and a second switch. A gate and a source of the first transistor are electrically connected to each other. A first terminal of the first capacitor is electrically connected to the source. A second terminal and the first output terminal of the first capacitor are electrically connected to a back gate of the first transistor. The first switch controls input of a first voltage to the back gate. A second voltage is input to a drain of the first transistor. The second switch controls input of a third voltage to the source.

Abstract: To improve field-effect mobility and reliability in a transistor including an oxide semiconductor film. A semiconductor device includes a transistor including an oxide semiconductor film. The transistor includes a region where the maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 40 and smaller than 150; a region where the threshold voltage is higher than or equal to minus 1 V and lower than or equal to 1 V; and a region where the S value is smaller than 0.3 V/decade.

Abstract: A minute transistor is provided that includes a first insulator, a second insulator, a first, conductor, a second conductor, and third conductor, in which an angle is formed between a side surface of the first insulator and a top surface of the first conductor, and a length between the first conductor and a surface of the second conductor closest to the first conductor is at least greater than a length between the first conductor and the third conductor.

Abstract: A semiconductor device having high operation frequency is provided. The semiconductor device includes a transistor including a first conductive layer, a first insulating layer, a second insulating layer, a first oxide, a second oxide, a third oxide, a third insulating layer, and a second conductive layer that are stacked in this order, and a fourth insulating layer. The first conductive layer and the second conductive layer include a region overlapping with the second oxide. In a channel width direction of the transistor, a level of the bottom surface of the second oxide is from more than or equal to ?5 nm to less than 0 nm when a level of a region of the bottom surface of the second conductive layer which does not overlap with the second oxide is regarded as a reference.

Abstract: A minute transistor is provided that includes a first insulator, a second insulator, a first, conductor, a second conductor, and third conductor, in which an angle is formed between a side surface of the first insulator and a top surface of the first conductor, and a length between the first conductor and a surface of the second conductor closest to the first conductor is at least greater than a length between the first conductor and the third conductor.

Abstract: A semiconductor device with excellent electric characteristics is provided. The semiconductor device includes an oxide in a channel formation region. The semiconductor device includes the oxide over a substrate, a first insulator over the oxide, a second insulator over the first insulator, a third insulator, and a conductor over the third insulator. The oxide and the first insulator are in contact with each other in a region. An opening exposing the oxide is provided in the first insulator and the second insulator. The third insulator is placed to cover an inner wall and a bottom surface of the opening. The conductor is placed to fill the opening. The conductor has a region overlapping with the oxide with the third insulator between the conductor and the oxide. The first insulator contains an element other than a main component of the oxide.

Abstract: A semiconductor device that stably operates even at high temperature is provided. The semiconductor device includes a metal oxide, an insulating layer, a first conductive layer, a second conductive layer, and a third conductive layer. The metal oxide includes a first region, a second region, and a third region. The first region overlaps with the first conductive layer. The second region overlaps with the second conductive layer. The third region overlaps with the third conductive layer with the insulating layer interposed therebetween. The value of the ratio of the carrier concentration in the first region to the carrier concentration in the third region is 100 or more. The value of the ratio of the carrier concentration in the second region to the carrier concentration in the third region is 100 or more.

Abstract: A semiconductor device having high operation frequency is provided. The semiconductor device includes a transistor including a first conductive layer, a first insulating layer, a second insulating layer, a first oxide, a second oxide, a third oxide, a third insulating layer, and a second conductive layer that are stacked in this order, and a fourth insulating layer. The first conductive layer and the second conductive layer include a region overlapping with the second oxide. In a channel width direction of the transistor, a level of the bottom surface of the second oxide is from more than or equal to ?5 nm to less than 0 nm when a level of a region of the bottom surface of the second conductive layer which does not overlap with the second oxide is regarded as a reference.

Abstract: A semiconductor device capable of obtaining the threshold voltage of a transistor is provided. The semiconductor device includes a first transistor, a first capacitor, a first output terminal, a first switch, and a second switch. A gate and a source of the first transistor are electrically connected to each other. A first terminal of the first capacitor is electrically connected to the source. A second terminal and the first output terminal of the first capacitor are electrically connected to a back gate of the first transistor. The first switch controls input of a first voltage to the back gate. A second voltage is input to a drain of the first transistor. The second switch controls input of a third voltage to the source.

Abstract: A minute transistor is provided. A semiconductor device includes a semiconductor over a substrate, a first conductor and a second conductor over the semiconductor, a first insulator over the first conductor and the second conductor, a second insulator over the semiconductor, a third insulator over the second insulator, and a third conductor over the third insulator. The third insulator is in contact with a side surface of the first insulator. The semiconductor includes a first region where the semiconductor overlaps with a bottom surface of the first conductor, a second region where the semiconductor overlaps with a bottom surface of the second conductor, and a third region where the semiconductor overlaps with a bottom surface of the third conductor. The length between a top surface of the semiconductor and the bottom surface of the third conductor is longer than the length between the first region and the third region.

Abstract: To improve field-effect mobility and reliability in a transistor including an oxide semiconductor film. A semiconductor device includes a transistor including an oxide semiconductor film. The transistor includes a region where the maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 40 and smaller than 150; a region where the threshold voltage is higher than or equal to minus 1 V and lower than or equal to 1 V; and a region where the S value is smaller than 0.3 V/decade.

Abstract: A semiconductor device with excellent electric characteristics is provided. The semiconductor device includes an oxide in a channel formation region. The semiconductor device includes the oxide over a substrate, a first insulator over the oxide, a second insulator over the first insulator, a third insulator, and a conductor over the third insulator. The oxide and the first insulator are in contact with each other in a region. An opening exposing the oxide is provided in the first insulator and the second insulator. The third insulator is placed to cover an inner wall and a bottom surface of the opening. The conductor is placed to fill the opening. The conductor has a region overlapping with the oxide with the third insulator between the conductor and the oxide. The first insulator contains an element other than a main component of the oxide.

Abstract: To improve field-effect mobility and reliability in a transistor including an oxide semiconductor film. A semiconductor device includes a transistor including an oxide semiconductor film. The transistor includes a region where the maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 40 and smaller than 150; a region where the threshold voltage is higher than or equal to minus 1 V and lower than or equal to 1 V; and a region where the S value is smaller than 0.3 V/decade.

Abstract: A minute transistor with low parasitic capacitance, high frequency characteristics, favorable electrical characteristics, stable electrical characteristics, and low off-state current is provided. A semiconductor device includes a semiconductor over a substrate, a source and a drain over the semiconductor, a first insulator over the source and the drain, a second insulator over the semiconductor, a third insulator in contact with a side surface of the first insulator and over the second insulator, and a gate over the third insulator. The semiconductor includes a first region overlapping with the source, a second region overlapping with the drain, and a third region overlapping with the gate. The length between a top surface of the third region of the semiconductor and a bottom surface of the gate is longer than the length between the first region and the third region.