Abstract: A semiconductor device that can be highly integrated is provided. The semiconductor device includes a transistor, an interlayer film, and a first conductor. The transistor includes an oxide over a first insulator; a second conductor over the oxide; a second insulator provided between the oxide and the second conductor and in contact with a side surface of the second conductor; and a third insulator provided for the side surface of the second conductor with the second insulator therebetween. The oxide includes a first region, a second region, and a third region. The first region overlaps with the second conductor. The second region is provided between the first region and the third region. The third region has a lower resistance than the second region. The second region has a lower resistance than the first region. The interlayer film is provided over the first insulator and the oxide. The first conductor is electrically connected to the third region.

Abstract: A semiconductor device having a reduced amount of oxygen vacancy in a channel formation region of an oxide semiconductor is provided. Further, a semiconductor device which includes an oxide semiconductor and has improved electric characteristics is provided. Furthermore, a methods for manufacturing the semiconductor device is provided. An oxide semiconductor film is formed; a conductive film is formed over the oxide semiconductor film at the same time as forming a low-resistance region between the oxide semiconductor film and the conductive film; the conductive film is processed to form a source electrode and a drain electrode; and oxygen is added to the low-resistance region between the source electrode and the drain electrode, so that a channel formation region having a higher resistance than the low-resistance region is formed and a first low-resistance region and a second low-resistance region between which the channel formation region is positioned are formed.

Abstract: A semiconductor device that can be highly integrated is provided. The semiconductor device includes a first transistor, a second transistor, a first capacitor, and a second capacitor. The first transistor includes an oxide over a first insulator, a second insulator over the oxide, a first conductor over the second insulator, a third insulator over the first conductor, a fourth insulator in contact with the second insulator, the first conductor, and the third insulator, and a fifth insulator in contact with the fourth insulator. The second transistor includes an oxide over the first insulator, a sixth insulator over the oxide, a second conductor over the sixth insulator, a seventh insulator over the second conductor, an eighth insulator in contact with the sixth insulator, the second conductor, and the seventh insulator, and a ninth insulator in contact with the eighth insulator. The first capacitor includes an oxide, a tenth insulator over the oxide, and a third conductor over the tenth insulator.

Abstract: A semiconductor device with a high threshold voltage is provided. A first conductor positioned over a substrate, a first insulator positioned over the first conductor, a first oxide positioned in contact with the top surface of the first insulator, a second insulator positioned in contact with the top surface of the first oxide, a second oxide positioned over the second insulator, a third insulator positioned over the second oxide, and a second conductor positioned over the third insulator are included. A mixed layer is formed between the first insulator and the first oxide. The mixed layer contains at least one of atoms contained in the first insulator and at least one of atoms contained in the first oxide. The mixed layer has fixed negative charge.

Abstract: A transistor includes oxide semiconductor stacked layers between a first gate electrode layer and a second gate electrode layer through an insulating layer interposed between the first gate electrode layer and the oxide semiconductor stacked layers and an insulating layer interposed between the second gate electrode layer and the oxide semiconductor stacked layers. The thickness of a channel formation region is smaller than the other regions in the oxide semiconductor stacked layers. Further in this transistor, one of the gate electrode layers is provided as what is called a back gate for controlling the threshold voltage. Controlling the potential applied to the back gate enables control of the threshold voltage of the transistor, which makes it easy to maintain the normally-off characteristics of the transistor.

Abstract: A transistor includes oxide semiconductor stacked layers between a first gate electrode layer and a second gate electrode layer through an insulating layer interposed between the first gate electrode layer and the oxide semiconductor stacked layers and an insulating layer interposed between the second gate electrode layer and the oxide semiconductor stacked layers. The thickness of a channel formation region is smaller than the other regions in the oxide semiconductor stacked layers. Further in this transistor, one of the gate electrode layers is provided as what is called a back gate for controlling the threshold voltage. Controlling the potential applied to the back gate enables control of the threshold voltage of the transistor, which makes it easy to maintain the normally-off characteristics of the transistor.

Abstract: Provided is a storage device that achieves both retention operation at high temperatures and high-speed operation at low temperatures. The storage device includes a driver circuit and a plurality of memory cells, and the memory cell includes a transistor and a capacitor; the transistor includes a metal oxide in a channel formation region. In the case where the transistor includes a first gate and a second gate, the driver circuit has a function of driving the second gate, and the driver circuit outputs a potential corresponding to the temperature of the storage device or the temperature of an environment where the storage device is placed to the second gate in a period during which the memory cell retains data.

Abstract: To reduce defects in an oxide semiconductor film in a semiconductor device. To improve the electrical characteristics and the reliability of a semiconductor device including an oxide semiconductor film. In a semiconductor device including a transistor including a gate electrode formed over a substrate, a gate insulating film covering the gate electrode, a multilayer film overlapping with the gate electrode with the gate insulating film provided therebetween, and a pair of electrodes in contact with the multilayer film, a first oxide insulating film covering the transistor, and a second oxide insulating film formed over the first oxide insulating film, the multilayer film includes an oxide semiconductor film and an oxide film containing In or Ga, the first oxide insulating film is an oxide insulating film through which oxygen is permeated, and the second oxide insulating film is an oxide insulating film containing more oxygen than that in the stoichiometric composition.

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 reduce defects in an oxide semiconductor film in a semiconductor device. To improve the electrical characteristics and the reliability of a semiconductor device including an oxide semiconductor film. In a semiconductor device including a transistor including a gate electrode formed over a substrate, a gate insulating film covering the gate electrode, a multilayer film overlapping with the gate electrode with the gate insulating film provided therebetween, and a pair of electrodes in contact with the multilayer film, a first oxide insulating film covering the transistor, and a second oxide insulating film formed over the first oxide insulating film, the multilayer film includes an oxide semiconductor film and an oxide film containing In or Ga, the first oxide insulating film is an oxide insulating film through which oxygen is permeated, and the second oxide insulating film is an oxide insulating film containing more oxygen than that in the stoichiometric composition.

Abstract: Provided is a semiconductor device having favorable reliability.

Abstract: A semiconductor device having a reduced amount of oxygen vacancy in a channel formation region of an oxide semiconductor is provided. Further, a semiconductor device which includes an oxide semiconductor and has improved electric characteristics is provided. Furthermore, a methods for manufacturing the semiconductor device is provided. An oxide semiconductor film is formed; a conductive film is formed over the oxide semiconductor film at the same time as forming a low-resistance region between the oxide semiconductor film and the conductive film; the conductive film is processed to form a source electrode and a drain electrode; and oxygen is added to the low-resistance region between the source electrode and the drain electrode, so that a channel formation region having a higher resistance than the low-resistance region is formed and a first low-resistance region and a second low-resistance region between which the channel formation region is positioned are formed.

Abstract: A semiconductor device that can be miniaturized or highly integrated is provided. The semiconductor device includes an oxide; a first conductor and a second conductor apart from each other over the oxide; a first insulator over the first conductor and the second conductor, in which an opening is formed to overlap with a region between the first conductor and the second conductor; a third conductor in the opening; and a second insulator between the oxide, the first conductor, the second conductor, and the first insulator and the third conductor. The second insulator has a first thickness between the oxide and the third conductor, and has a second thickness between the first conductor or the second conductor and the third conductor. The first thickness is smaller than the second thickness.

Abstract: A transistor in which a short-channel effect is not substantially caused and which has switching characteristics even in the case where the channel length is short is provided. Further, a highly integrated semiconductor device including the transistor is provided. A short-channel effect which is caused in a transistor including silicon is not substantially caused in the transistor including an oxide semiconductor film. The channel length of the transistor including the oxide semiconductor film is greater than or equal to 5 nm and less than 60 nm, and the channel width thereof is greater than or equal to 5 nm and less than 200 nm. At this time, the channel width is made 0.5 to 10 times as large as the channel length.

Abstract: A first transistor, a second transistor, a capacitor, and first to third conductors are included. The first transistor includes a first gate, a source, and a drain. The second transistor includes a second gate, a third gate over the second gate, first and second low-resistance regions, and an oxide sandwiched between the second gate and the third gate. The capacitor includes a first electrode, a second electrode, and an insulator sandwiched therebetween. The first low-resistance region overlaps with the first gate. The first conductor is electrically connected to the first gate and is connected to a bottom surface of the first low-resistance region. The capacitor overlaps with the first low-resistance region. The second conductor is electrically connected to the drain. The third conductor overlaps with the second conductor and is connected to the second conductor and a side surface of the second low-resistance region.

Abstract: A semiconductor device which has favorable electrical characteristics and can be highly integrated is provided. The semiconductor device includes a first insulator; an oxide over the first insulator; a second insulator over the oxide; a first conductor over the second insulator; a third insulator in contact with a top surface of the first insulator, a side surface of the oxide, a top surface of the oxide, a side surface of the second insulator, and a side surface of the first conductor; and a fourth insulator over the third insulator. The third insulator includes an opening exposing the first insulator, and the fourth insulator is in contact with the first insulator through the opening.

Abstract: A semiconductor device that can be highly integrated is provided. The semiconductor device includes a transistor, an interlayer film, and a first conductor. The transistor includes an oxide over a first insulator; a second conductor over the oxide; a second insulator provided between the oxide and the second conductor and in contact with a side surface of the second conductor; and a third insulator provided for the side surface of the second conductor with the second insulator therebetween. The oxide includes a first region, a second region, and a third region. The first region overlaps with the second conductor. The second region is provided between the first region and the third region. The third region has a lower resistance than the second region. The second region has a lower resistance than the first region. The interlayer film is provided over the first insulator and the oxide. The first conductor is electrically connected to the third region.

Abstract: A semiconductor device having favorable electrical characteristics is provided. The semiconductor device includes an oxide; a first conductor and a second conductor over the oxide; a third conductor over the oxide; a first insulator provided between the oxide and the third conductor and covering a side surface of the third conductor; a second insulator over the third conductor and the first insulator; a third insulator positioned over the first conductor and at a side surface of the second insulator; a fourth insulator positioned over the second conductor and at a side surface of the second insulator; a fourth conductor being in contact with a top surface and a side surface of the third insulator and electrically connected to the first conductor; and a fifth conductor being in contact with a top surface and a side surface of the fourth insulator and electrically connected to the second conductor.

Abstract: A semiconductor device having a reduced amount of oxygen vacancy in a channel formation region of an oxide semiconductor is provided. Further, a semiconductor device which includes an oxide semiconductor and has improved electric characteristics is provided. Furthermore, a methods for manufacturing the semiconductor device is provided. An oxide semiconductor film is formed; a conductive film is formed over the oxide semiconductor film at the same time as forming a low-resistance region between the oxide semiconductor film and the conductive film; the conductive film is processed to form a source electrode and a drain electrode; and oxygen is added to the low-resistance region between the source electrode and the drain electrode, so that a channel formation region having a higher resistance than the low-resistance region is formed and a first low-resistance region and a second low-resistance region between which the channel formation region is positioned are formed.

Abstract: A miniaturized transistor with reduced parasitic capacitance and highly stable electrical characteristics is provided. High performance and high reliability of a semiconductor device including the transistor is achieved. A first conductor is formed over a substrate, a first insulator is formed over the first conductor, a layer that retains fixed charges is formed over the first insulator, a second insulator is formed over the layer that retains fixed charges, and a transistor is formed over the second insulator. Threshold voltage Vth is controlled by appropriate adjustment of the thicknesses of the first insulator, the second insulator, and the layer that retains fixed charges.