Abstract: A miniaturized transistor, a transistor with low parasitic capacitance, a transistor with high frequency characteristics, or a semiconductor device including the transistor is provided. The semiconductor device includes a first insulator, an oxide semiconductor over the first insulator, a first conductor and a second conductor that are in contact with the oxide semiconductor, a second insulator that is over the first and second conductors and has an opening reaching the oxide semiconductor, a third insulator over the oxide semiconductor and the second insulator, and a fourth conductor over the third insulator. The first conductor includes a first region and a second region. The second conductor includes a third region and a fourth region. The second region faces the third region with the first conductor and the first insulator interposed therebetween. The second region is thinner than the first region. The third region is thinner than the fourth region.

Abstract: A semiconductor device includes a first insulating layer over a substrate, a first metal oxide layer over the first insulating layer, an oxide semiconductor layer over the first metal oxide layer, a second metal oxide layer over the oxide semiconductor layer, a gate insulating layer over the second metal oxide layer, a second insulating layer over the second metal oxide layer, and a gate electrode layer over the gate insulating layer. The gate insulating layer includes a region in contact with a side surface of the gate electrode layer. The second insulating layer includes a region in contact with the gate insulating layer. The oxide semiconductor layer includes first to third regions. The first region includes a region overlapping with the gate electrode layer. The second region, which is between the first and third regions, includes a region overlapping with the gate insulating layer or the second insulating layer.

Abstract: A miniaturized transistor is provided. A transistor with low parasitic capacitance is provided. A transistor having high frequency characteristics is provided. A transistor having a large amount of on-state current is provided. A semiconductor device including the transistor is provided. A semiconductor device with high integration is provided. A novel capacitor is provided. The capacitor includes a first conductor, a second conductor, and an insulator. The first conductor includes a region overlapping with the second conductor with the insulator provided therebetween. The first conductor includes tungsten and silicon. The insulator includes a silicon oxide film that is formed by oxidizing the first conductor.

Abstract: A semiconductor device using an oxide semiconductor is provided with stable electric characteristics to improve the reliability. In a manufacturing process of a transistor including an oxide semiconductor film, an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a first crystalline oxide semiconductor film) is formed; oxygen is added to the oxide semiconductor film to amorphize at least part of the oxide semiconductor film, so that an amorphous oxide semiconductor film containing an excess of oxygen is formed; an aluminum oxide film is formed over the amorphous oxide semiconductor film; and heat treatment is performed thereon to crystallize at least part of the amorphous oxide semiconductor film, so that an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a second crystalline oxide semiconductor film) is formed.

Abstract: A semiconductor device includes a first oxide insulating layer over a first insulating layer, an oxide semiconductor layer over the first oxide insulating layer, a source electrode layer and a drain electrode layer over the oxide semiconductor layer, a second insulating layer over the source electrode layer and the drain electrode layer, a second oxide insulating layer over the oxide semiconductor layer, a gate insulating layer over the second oxide insulating layer, a gate electrode layer over the gate insulating layer, and a third insulating layer over the second insulating layer, the second oxide insulating layer, the gate insulating layer, and the gate electrode layer. A side surface portion of the second insulating layer is in contact with the second oxide insulating layer. The gate electrode layer includes a first region and a second region. The first region has a width larger than that of the second region.

Abstract: A semiconductor device includes a first insulating layer over a substrate, a first metal oxide layer over the first insulating layer, an oxide semiconductor layer over the first metal oxide layer, a second metal oxide layer over the oxide semiconductor layer, a gate insulating layer over the second metal oxide layer, a second insulating layer over the second metal oxide layer, and a gate electrode layer over the gate insulating layer. The gate insulating layer includes a region in contact with a side surface of the gate electrode layer. The second insulating layer includes a region in contact with the gate insulating layer. The oxide semiconductor layer includes first to third regions. The first region includes a region overlapping with the gate electrode layer. The second region, which is between the first and third regions, includes a region overlapping with the gate insulating layer or the second insulating layer.

Abstract: A semiconductor device in which parasitic capacitance is reduced is provided. A first insulating layer is deposited over a substrate. A first oxide insulating layer and an oxide semiconductor layer are deposited over the first insulating layer. A second oxide insulating layer is deposited over the oxide semiconductor layer and the first insulating layer. A second insulating layer and a first conductive layer are deposited over the second oxide insulating layer. A gate electrode layer, a gate insulating layer, and a third oxide insulating layer are formed by etching. A sidewall insulating layer including a region in contact with a side surface of the gate electrode layer is formed. A second conductive layer is deposited over the gate electrode layer, the sidewall insulating layer, the oxide semiconductor layer, and the first insulating layer. A third conductive layer is deposited over the second conductive layer. A low-resistance region is formed in the oxide semiconductor layer by performing heat treatment.

Abstract: To provide a semiconductor device that includes an oxide semiconductor and is miniaturized while keeping good electrical properties. In the semiconductor device, an oxide semiconductor layer filling a groove is surrounded by insulating layers including an aluminum oxide film containing excess oxygen. Excess oxygen contained in the aluminum oxide film is supplied to the oxide semiconductor layer, in which a channel is formed, by heat treatment in a manufacturing process of the semiconductor device. Moreover, the aluminum oxide film forms a barrier against oxygen and hydrogen, which inhibits the removal of oxygen from the oxide semiconductor layer surrounded by the insulating layers including an aluminum oxide film and the entry of impurities such as hydrogen in the oxide semiconductor layer. Thus, a highly purified intrinsic oxide semiconductor layer can be obtained. The threshold voltage is controlled effectively by gate electrode layers formed over and under the oxide semiconductor layer.

Abstract: A miniaturized transistor is provided. A transistor with low parasitic capacitance is provided. A transistor having high frequency characteristics is provided. A transistor having a large amount of on-state current is provided. A semiconductor device including the transistor is provided. A semiconductor device with high integration is provided. A novel capacitor is provided. The capacitor includes a first conductor, a second conductor, and an insulator. The first conductor includes a region overlapping with the second conductor with the insulator provided therebetween. The first conductor includes tungsten and silicon. The insulator includes a silicon oxide film that is formed by oxidizing the first conductor.

Abstract: To provide a semiconductor device that includes an oxide semiconductor and is miniaturized while keeping good electrical properties. In the semiconductor device, an oxide semiconductor layer is surrounded by an insulating layer including an aluminum oxide film containing excess oxygen. Excess oxygen in the aluminum oxide film is supplied to the oxide semiconductor layer including a channel by heat treatment in a manufacturing process of the semiconductor device. Furthermore, the aluminum oxide film forms a barrier against oxygen and hydrogen. It is thus possible to suppress the removal of oxygen from the oxide semiconductor layer surrounded by the insulating layer including an aluminum oxide film, and the entry of impurities such as hydrogen into the oxide semiconductor layer; as a result, the oxide semiconductor layer can be made highly intrinsic. In addition, gate electrode layers over and under the oxide semiconductor layer control the threshold voltage effectively.

Abstract: To provide a transistor having a high on-state current. A semiconductor device includes a first insulator containing excess oxygen, a first oxide semiconductor over the first insulator, a second oxide semiconductor over the first oxide semiconductor, a first conductor and a second conductor which are over the second oxide semiconductor and are separated from each other, a third oxide semiconductor in contact with side surfaces of the first oxide semiconductor, a top surface and side surfaces of the second oxide semiconductor, a top surface of the first conductor, and a top surface of the second conductor, a second insulator over the third oxide semiconductor, and a third conductor facing a top surface and side surfaces of the second oxide semiconductor with the second insulator and the third oxide semiconductor therebetween. The first oxide semiconductor has a higher oxygen-transmitting property than the third oxide semiconductor.

Abstract: To provide a semiconductor device capable of retaining data for a long time. The semiconductor device includes a first transistor, an insulator covering the first transistor, and a second transistor over the insulator. The first transistor includes a first gate electrode, a second gate electrode overlapping with the first gate electrode, and a semiconductor between the first gate electrode and the second gate electrode. The first gate electrode is electrically connected to one of a source and a drain of the second transistor.

Abstract: A semiconductor device includes a first oxide insulating layer over a first insulating layer, an oxide semiconductor layer over the first oxide insulating layer, a source electrode layer and a drain electrode layer over the oxide semiconductor layer, a second insulating layer over the source electrode layer and the drain electrode layer, a second oxide insulating layer over the oxide semiconductor layer, a gate insulating layer over the second oxide insulating layer, a gate electrode layer over the gate insulating layer, and a third insulating layer over the second insulating layer, the second oxide insulating layer, the gate insulating layer, and the gate electrode layer. A side surface portion of the second insulating layer is in contact with the second oxide insulating layer. The gate electrode layer includes a first region and a second region. The first region has a width larger than that of the second region.

Abstract: A transistor with favorable electrical characteristics is provided. A transistor with stable electrical characteristics is provided. A semiconductor device having a high degree of integration is provided. Side surfaces of an oxide semiconductor layer in which a channel is formed are covered with an oxide semiconductor layer, whereby impurity diffusion from the side surfaces of the oxide semiconductor into the inside can be prevented. A gate electrode is formed by a damascene process, whereby transistors can be miniaturized and formed at a high density.

Abstract: A semiconductor device using an oxide semiconductor is provided with stable electric characteristics to improve the reliability. In a manufacturing process of a transistor including an oxide semiconductor film, an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a first crystalline oxide semiconductor film) is formed; oxygen is added to the oxide semiconductor film to amorphize at least part of the oxide semiconductor film, so that an amorphous oxide semiconductor film containing an excess of oxygen is formed; an aluminum oxide film is formed over the amorphous oxide semiconductor film; and heat treatment is performed thereon to crystallize at least part of the amorphous oxide semiconductor film, so that an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a second crystalline oxide semiconductor film) is formed.

Abstract: A semiconductor device in which parasitic capacitance is reduced is provided. A first insulating layer is deposited over a substrate. A first oxide insulating layer and an oxide semiconductor layer are deposited over the first insulating layer. A second oxide insulating layer is deposited over the oxide semiconductor layer and the first insulating layer. A second insulating layer and a first conductive layer are deposited over the second oxide insulating layer. A gate electrode layer, a gate insulating layer, and a third oxide insulating layer are formed by etching. A sidewall insulating layer including a region in contact with a side surface of the gate electrode layer is formed. A second conductive layer is deposited over the gate electrode layer, the sidewall insulating layer, the oxide semiconductor layer, and the first insulating layer. A third conductive layer is deposited over the second conductive layer. A low-resistance region is formed in the oxide semiconductor layer by performing heat treatment.

Abstract: To provide a transistor having a high on-state current. A semiconductor device includes a first insulator containing excess oxygen, a first oxide semiconductor over the first insulator, a second oxide semiconductor over the first oxide semiconductor, a first conductor and a second conductor which are over the second oxide semiconductor and are separated from each other, a third oxide semiconductor in contact with side surfaces of the first oxide semiconductor, a top surface and side surfaces of the second oxide semiconductor, a top surface of the first conductor, and a top surface of the second conductor, a second insulator over the third oxide semiconductor, and a third conductor facing a top surface and side surfaces of the second oxide semiconductor with the second insulator and the third oxide semiconductor therebetween. The first oxide semiconductor has a higher oxygen-transmitting property than the third oxide semiconductor.

Abstract: A miniaturized transistor, a transistor with low parasitic capacitance, a transistor with high frequency characteristics, or a semiconductor device including the transistor is provided. The semiconductor device includes a first insulator, an oxide semiconductor over the first insulator, a first conductor and a second conductor that are in contact with the oxide semiconductor, a second insulator that is over the first and second conductors and has an opening reaching the oxide semiconductor, a third insulator over the oxide semiconductor and the second insulator, and a fourth conductor over the third insulator. The first conductor includes a first region and a second region. The second conductor includes a third region and a fourth region. The second region faces the third region with the first conductor and the first insulator interposed therebetween. The second region is thinner than the first region. The third region is thinner than the fourth region.

Abstract: A first conductive film overlapping with an oxide semiconductor film is formed over a gate insulating film, a gate electrode is formed by selectively etching the first conductive film using a resist subjected to electron beam exposure, a first insulating film is formed over the gate insulating film and the gate electrode, removing a part of the first insulating film while the gate electrode is not exposed, an anti-reflective film is formed over the first insulating film, the anti-reflective film, the first insulating film and the gate insulating film are selectively etched using a resist subjected to electron beam exposure, and a source electrode in contact with one end of the oxide semiconductor film and one end of the first insulating film and a drain electrode in contact with the other end of the oxide semiconductor film and the other end of the first insulating film are formed.

Abstract: A semiconductor device includes a first insulating layer over a substrate, a first metal oxide layer over the first insulating layer, an oxide semiconductor layer over the first metal oxide layer, a second metal oxide layer over the oxide semiconductor layer, a gate insulating layer over the second metal oxide layer, a second insulating layer over the second metal oxide layer, and a gate electrode layer over the gate insulating layer. The gate insulating layer includes a region in contact with a side surface of the gate electrode layer. The second insulating layer includes a region in contact with the gate insulating layer. The oxide semiconductor layer includes first to third regions. The first region includes a region overlapping with the gate electrode layer. The second region, which is between the first and third regions, includes a region overlapping with the gate insulating layer or the second insulating layer.