Abstract: A semiconductor device with favorable electrical characteristics is provided. A highly reliable semiconductor device is provided. The semiconductor device includes a semiconductor layer, a first insulating layer over the semiconductor layer, and a conductive layer over the first insulating layer. The semiconductor layer includes a first region, a pair of second regions, a pair of third regions, and a pair of fourth regions. The second regions sandwich the first region, the third regions sandwich the first region and the second regions, and the fourth regions sandwich the first region, the second regions, and the third regions. The first region includes a region overlapping with the first insulating layer and the conductive layer, the second regions and the third regions each include a region overlapping with the first insulating layer and not overlapping with the conductive layer, and the fourth regions overlap with neither the first insulating layer nor the conductive layer.

Abstract: A semiconductor device with favorable electrical characteristics is provided. A highly reliable semiconductor device is provided. The semiconductor device includes a semiconductor layer, a first insulating layer over the semiconductor layer, and a conductive layer over the first insulating layer. The semiconductor layer includes a first region, a pair of second regions, a pair of third regions, and a pair of fourth regions. The second regions sandwich the first region, the third regions sandwich the first region and the second regions, and the fourth regions sandwich the first region, the second regions, and the third regions. The first region includes a region overlapping with the first insulating layer and the conductive layer, the second regions and the third regions each include a region overlapping with the first insulating layer and not overlapping with the conductive layer, and the fourth regions overlap with neither the first insulating layer nor the conductive layer.

Abstract: A semiconductor device that occupies a small area is provided. The semiconductor device includes a first conductive layer, a second conductive layer over the first conductive layer, a first insulating layer over the second conductive layer, a semiconductor layer and a third conductive layer over the first insulating layer, a second insulating layer over the semiconductor layer and the third conductive layer, and a fourth conductive layer over the second insulating layer; at least part of the second conductive layer is in contact with a top surface of the first conductive layer; the semiconductor layer is in contact with the top surface of the first conductive layer, a side surface of the second conductive layer, the third conductive layer, and a side surface of the first insulating layer; and the fourth conductive layer overlaps with the semiconductor layer with the second insulating layer therebetween.

Abstract: A semiconductor device having a high degree of integration is provided. A first and second transistors which are electrically connected to each other and a first insulating layer are included. The first transistor includes a first semiconductor layer, a second insulating layer, and a first to third conductive layers. The second transistor includes a second semiconductor layer, a third insulating layer, and a fourth to sixth conductive layers. The first insulating layer is positioned over the first conductive layer and includes an opening reaching the first conductive layer. The second conductive layer is positioned over the first insulating layer. The first semiconductor layer is in contact with a top surface of the first conductive layer, an inner wall of the opening, and the second conductive layer. The third conductive layer is positioned over the second insulating layer to overlap with the inner wall of the opening. The third insulating layer is positioned over the fourth conductive layer.

Abstract: A semiconductor device (10) having a high degree of integration is provided. A first and a second transistors which are electrically connected to each other and a first insulating layer (110) are included. The first transistor (M2) includes a first semiconductor layer (108), a second insulating layer (106), and a first to a third conductive layers. The second transistor (M1) includes a second semiconductor layer (109), a third insulating layer (106), and a fourth to a sixth conductive layers. The first insulating layer is positioned over the first conductive layer (112a) and includes an opening reaching the first conductive layer. The second conductive layer (112b) is positioned over the first insulating layer. The first semiconductor layer is in contact with a top surface of the first conductive layer, an inner wall of the opening, and the second conductive layer. The third conductive layer (104) is positioned over the second insulating layer to overlap with the inner wall of the opening.

Abstract: A semiconductor device having a high degree of integration is provided. The semiconductor device includes a first and a second transistor, and an insulating layer. The first transistor includes a source electrode, a drain electrode over the insulating layer over the source electrode, a first semiconductor layer in contact with a top surface of the source electrode, an inner wall of an opening provided in the insulating layer, and a top surface of the drain electrode, a first gate insulating layer in contact with a top surface and a side surface of the first semiconductor layer, and a first gate electrode over the first gate insulating layer that includes a region overlapping with the inner wall of the opening.

Abstract: A semiconductor device with favorable electrical characteristics is provided. A highly reliable semiconductor device is provided. The semiconductor device includes a semiconductor layer, a first insulating layer over the semiconductor layer, and a conductive layer over the first insulating layer. The semiconductor layer includes a first region, a pair of second regions, a pair of third regions, and a pair of fourth regions. The second regions sandwich the first region, the third regions sandwich the first region and the second regions, and the fourth regions sandwich the first region, the second regions, and the third regions. The first region includes a region overlapping with the first insulating layer and the conductive layer, the second regions and the third regions each include a region overlapping with the first insulating layer and not overlapping with the conductive layer, and the fourth regions overlap with neither the first insulating layer nor the conductive layer.

Abstract: A highly reliable semiconductor device which uses an oxide semiconductor film for a backplane is provided. A semiconductor device includes a first conductive film, a first insulating film over the first conductive film, an oxide semiconductor film which is over the first insulating film and overlaps with the first conductive film, a second insulating film over the oxide semiconductor film, and a pair of second conductive films electrically connected to the oxide semiconductor film through an opening portion included in the second insulating film. The second insulating film overlaps with a region of the oxide insulating film in which a carrier flows between the pair of second conductive films and overlaps with end portions of the oxide semiconductor film.

Abstract: A highly reliable semiconductor device which uses an oxide semiconductor film for a backplane is provided. A semiconductor device includes a first conductive film, a first insulating film over the first conductive film, an oxide semiconductor film which is over the first insulating film and overlaps with the first conductive film, a second insulating film over the oxide semiconductor film, and a pair of second conductive films electrically connected to the oxide semiconductor film through an opening portion included in the second insulating film. The second insulating film overlaps with a region of the oxide insulating film in which a carrier flows between the pair of second conductive films and overlaps with end portions of the oxide semiconductor film.

Abstract: A highly reliable semiconductor device which uses an oxide semiconductor film for a backplane is provided. A semiconductor device includes a first conductive film, a first insulating film over the first conductive film, an oxide semiconductor film which is over the first insulating film and overlaps with the first conductive film, a second insulating film over the oxide semiconductor film, and a pair of second conductive films electrically connected to the oxide semiconductor film through an opening portion included in the second insulating film. The second insulating film overlaps with a region of the oxide insulating film in which a carrier flows between the pair of second conductive films and overlaps with end portions of the oxide semiconductor film.

Abstract: A highly reliable semiconductor device which uses an oxide semiconductor film for a backplane is provided. A semiconductor device includes a first conductive film, a first insulating film over the first conductive film, an oxide semiconductor film which is over the first insulating film and overlaps with the first conductive film, a second insulating film over the oxide semiconductor film, and a pair of second conductive films electrically connected to the oxide semiconductor film through an opening portion included in the second insulating film. The second insulating film overlaps with a region of the oxide insulating film in which a carrier flows between the pair of second conductive films and overlaps with end portions of the oxide semiconductor film.