Abstract: A semiconductor device with a small variation in characteristics is provided. The semiconductor device includes a first insulator; a second insulator having an opening over the first insulator; a third insulator that has a first depressed portion and is provided inside the opening; a first oxide that has a second depressed portion and is provided inside the first depressed portion; a second oxide provided inside the second depressed portion; a first conductor and a second conductor that are electrically connected to the second oxide and are apart from each other; a fourth insulator over the second oxide; and a third conductor including a region overlapping with the second oxide with the fourth insulator therebetween. The second oxide includes a first region, a second region, and a third region sandwiched between the first region and the second region in a top view. The first conductor includes a region overlapping with the first region and the second insulator.

Abstract: A minute transistor is provided. A transistor with low parasitic capacitance is provided. A transistor having high frequency characteristics is provided. A semiconductor device including the transistor is provided. A semiconductor device includes an oxide semiconductor, a first conductor, a second conductor, a third conductor, a first insulator, and a second insulator. The first conductor overlaps with the oxide semiconductor with the first insulator positioned therebetween. The second insulator has an opening and a side surface of the second insulator overlaps with a side surface of the first conductor in the opening with the first insulator positioned therebetween. Part of a surface of the second conductor and part of a surface of the third conductor are in contact with the first insulator in the opening. The oxide semiconductor overlaps with the second conductor and the third conductor.

Abstract: A semiconductor device in which variations in characteristics, deterioration of elements, and abnormality in shape are inhibited is provided. The semiconductor device includes a first region including a plurality of elements and a second region including a plurality of dummy elements. The second region is provided in an outer edge of the first region, and the element and the dummy element each include an oxide semiconductor. The element and the dummy element have the same structure, and a structure body included in the element and a structure body included in the dummy element are formed with the same material and provided in the same layer. The oxide semiconductor includes In, an element M (M is Al, Ga, Y, or Sn), and Zn.

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: To provide a semiconductor device with less variations in characteristics. The semiconductor device includes a first circuit region and a second circuit region over a substrate, where the first circuit region includes a plurality of first transistors and a first insulator over the plurality of first transistors; the second circuit region includes a plurality of second transistors and a second insulator over the plurality of second transistors; the second insulator includes an opening portion; the first transistors and the second transistors each include an oxide semiconductor; a third insulator is positioned over and in contact with the first insulator and the second insulator; the first insulator, the second insulator, and the third insulator inhibit oxygen diffusion; and the density of the plurality of first transistors arranged in the first circuit region is higher than the density of the plurality of second transistors arranged in the second circuit region.

Abstract: A minute transistor is provided. A transistor with low parasitic capacitance is provided. A transistor having high frequency characteristics is provided. A semiconductor device including the transistor is provided. A semiconductor device includes an oxide semiconductor, a first conductor, a second conductor, a third conductor, a first insulator, and a second insulator. The first conductor overlaps with the oxide semiconductor with the first insulator positioned therebetween. The second insulator has an opening and a side surface of the second insulator overlaps with a side surface of the first conductor in the opening with the first insulator positioned therebetween. Part of a surface of the second conductor and part of a surface of the third conductor are in contact with the first insulator in the opening. The oxide semiconductor overlaps with the second conductor and the third conductor.

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 semiconductor device with a small variation in transistor characteristics is provided. The semiconductor device includes an oxide semiconductor, a first conductor and a second conductor over the oxide semiconductor, a first insulator in contact with a top surface of the first conductor, a second insulator in contact with a top surface of the second conductor, a third insulator which is positioned over the first insulator and the second insulator and has an opening overlapping with a region between the first conductor and the second conductor, a fourth insulator positioned over the oxide semiconductor and in the region between the first conductor and the second conductor, and a third conductor over the fourth insulator. Each of the first insulator and the second insulator is a metal oxide including an amorphous structure.

Abstract: A semiconductor device with high reliability is provided. The semiconductor device includes a first oxide; a first conductor, a second conductor, and a first insulator over the first oxide; and a third conductor over the first insulator. The first conductor includes a first crystal. The second conductor includes a crystal having the same crystal structure as the first crystal. The first crystal has (111) orientation with respect to a surface of the first oxide. The first oxide includes a second crystal. The second crystal has c-axis alignment with respect to a surface where the first oxide is formed. The lattice mismatch degree of the first crystal with respect to the second crystal is lower than or equal to 8 percent.

Abstract: A semiconductor device with favorable reliability is provided. The semiconductor device includes a first oxide, a second oxide, a first conductor, a second conductor, a third conductor, a first insulator, and a second insulator. The first conductor is provided in contact with a top surface of the first oxide. The second conductor is provided in contact with the top surface of the first oxide. The first insulator is provided over the first conductor and the second conductor. The second oxide is provided in contact with the top surface of the first oxide. The second insulator is provided over the second oxide. The third conductor is provided over the second insulator. The first insulator has a function of inhibiting diffusion of oxygen. The first oxide includes indium, an element M (M is gallium, yttrium, or tin), and zinc. The first oxide includes a first region overlapping with the third conductor.

Abstract: A transistor with a high on-state current and a semiconductor device with high productivity are provided. Included are a first oxide, a second oxide, a third oxide, and a fourth oxide over a first insulator; a first conductor over the third oxide; a second conductor over the fourth oxide; a second insulator over the first conductor; a third insulator over the second conductor; a fifth oxide positioned over the second oxide and between the third oxide and the fourth oxide; a sixth oxide over the fifth oxide; a fourth insulator over the sixth oxide; a third conductor over the fourth insulator; and a fifth insulator over the first insulator to the third insulator. The fifth oxide includes a region in contact with the second oxide to the fourth oxide and the first insulator. The sixth oxide includes a region in contact with the fifth oxide, the first conductor, and the second conductor. The fourth insulator includes a region in contact with at least the sixth oxide, the third conductor, and the fifth insulator.

Abstract: A semiconductor device with less variations in transistor characteristics is provided.

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: To provide a miniaturized semiconductor device with low power consumption. A method for manufacturing a wiring layer includes the following steps: forming a second insulator over a first insulator; forming a third insulator over the second insulator; forming an opening in the third insulator so that it reaches the second insulator; forming a first conductor over the third insulator and in the opening; forming a second conductor over the first conductor; and after forming the second conductor, performing polishing treatment to remove portions of the first and second conductors above a top surface of the third insulator. An end of the first conductor is at a level lower than or equal to the top level of the opening. The top surface of the second conductor is at a level lower than or equal to that of the end of the first conductor.

Abstract: A semiconductor device includes a first insulator; a first oxide over the first insulator; a second oxide over the first oxide; first and second conductors and a third oxide over the second oxide; a second insulator over the first conductor; a third insulator over the second conductor; first and second layers; and fourth to sixth insulators. The sixth insulator includes a region in contact with a top surface of the first insulator. The first layer includes a region in contact with side surfaces of the first and second oxides, a side surface of the first conductor, and the top surface of the first insulator. The second layer includes a region in contact with the side surfaces of the first and second oxides, a side surface of the second conductor, and the top surface of the first insulator.

Abstract: A semiconductor device with less variations in transistor characteristics is provided. A first insulator, first and second oxide films, a first conductive film, a first insulating film, and a second conductive film are deposited and processed to form a first and second oxides, a first conductive layer, a first insulating layer, and a second conductive layer. In the process, a layer is formed to cover the first and second oxides, the first conductive layer, the first insulating layer, and the second conductive layer. The second conductive layer and the layer are removed. A second insulating layer in contact with side surfaces of the first and second oxides, the first conductive layer, and the first insulating layer is formed, and a second insulator is formed thereover. An opening reaching the second oxide is formed in the first conductive layer, the first insulating layer, the second insulating layer, and the second insulator.

Abstract: The semiconductor device includes a first layer including a first transistor, a second layer including a first insulating film over the first layer, a third layer including a second insulating film over the second layer, and a fourth layer including a second transistor over the third layer. A first conductive film electrically connects the first transistor and the second transistor to each other through an opening provided in the first insulating film. A second conductive film electrically connects the first transistor, the second transistor, and the first conductive film to one another through an opening provided in the second insulating film. A channel formation region of the first transistor includes a single crystal semiconductor. A channel formation region of the second transistor includes an oxide semiconductor. The width of a bottom surface of the second conductive film is 5 nm or less.

Abstract: The semiconductor device includes a first layer including a first transistor, a second layer including a first insulating film over the first layer, a third layer including a second insulating film over the second layer, and a fourth layer including a second transistor over the third layer. A first conductive film electrically connects the first transistor and the second transistor to each other through an opening provided in the first insulating film. A second conductive film electrically connects the first transistor, the second transistor, and the first conductive film to one another through an opening provided in the second insulating film. A channel formation region of the first transistor includes a single crystal semiconductor. A channel formation region of the second transistor includes an oxide semiconductor. The width of a bottom surface of the second conductive film is 5 nm or less.

Abstract: A semiconductor device in which a variation of transistor characteristics is small is provided. The semiconductor device includes a transistor. The transistor includes a first insulator, a first oxide over the first insulator, a first conductor, a second conductor, and a second oxide, which is positioned between the first conductor and the second conductor, over the first oxide, a second insulator over the second oxide, and a third conductor over the second insulator. A top surface of the first oxide in a region overlapping with the third conductor is at a lower position than a position of a top surface of the first oxide in a region overlapping with the first conductor. The first oxide in the region overlapping with the third conductor has a curved surface between a side surface and the top surface of the first oxide, and the curvature radius of the curved surface is greater than or equal to 1 nm and less than or equal to 15 nm.

Abstract: A semiconductor device with small fluctuations in transistor characteristics can be provided. The semiconductor device includes a first oxide, a second oxide and a third oxide over the first oxide, a first conductor over the second oxide, a second conductor over the third oxide, a fourth oxide over the first oxide and between the second oxide and the third oxide, a first insulator over the fourth oxide, and a third conductor over the first insulator. The first oxide includes a groove in a region not overlapping with the second oxide and the third oxide. The first oxide includes a first layered crystal substantially parallel to the surface where the first oxide is formed. In the groove, the fourth oxide includes a second layered crystal substantially parallel to the surface where the first oxide is formed. A concentration of aluminum atoms at an interface between the first oxide and the fourth oxide and in the vicinity of the interface is less than or equal to 5.0 atomic %.