Abstract: A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Abstract: A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Abstract: A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Abstract: A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Abstract: A semiconductor device including a transistor and a wiring electrically connected to the transistor each of which has excellent electrical characteristics because of specific structures thereover is provided. A first conductive film, a first insulating film over the first conductive film, a second conductive film over the first insulating film, a second insulating film over the second conductive film, a third conductive film electrically connected to the first conductive film through an opening provided in the first insulating film and the second insulating film, and a third insulating film over the third conductive film are provided. The third conductive film includes indium, tin, and oxygen, and the third insulating film includes silicon and nitrogen and the number of ammonia molecules released from the third insulating film is less than or equal to 1×1015 molecules/cm3 by thermal desorption spectroscopy.

Abstract: To provide a highly flexible display device excellent in mass-productivity. A display device includes a flexible substrate, an adhesive layer over the substrate, a resin layer over the adhesive layer, an inorganic insulating layer over the resin layer, a transistor over the inorganic insulating layer, and a display element electrically connected to the transistor. The transistor includes an oxide semiconductor in a channel formation region. The resin layer includes sulfur.

Abstract: A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Abstract: A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Abstract: A semiconductor device including a transistor and a wiring electrically connected to the transistor each of which has excellent electrical characteristics because of specific structures thereover is provided. A first conductive film, a first insulating film over the first conductive film, a second conductive film over the first insulating film, a second insulating film over the second conductive film, a third conductive film electrically connected to the first conductive film through an opening provided in the first insulating film and the second insulating film, and a third insulating film over the third conductive film are provided. The third conductive film includes indium, tin, and oxygen, and the third insulating film includes silicon and nitrogen and the number of ammonia molecules released from the third insulating film is less than or equal to 1×1015 molecules/cm3 by thermal desorption spectroscopy.

Abstract: To provide a highly flexible display device excellent in mass-productivity. A display device includes a flexible substrate, an adhesive layer over the substrate, a resin layer over the adhesive layer, an inorganic insulating layer over the resin layer, a transistor over the inorganic insulating layer, and a display element electrically connected to the transistor. The transistor includes an oxide semiconductor in a channel formation region. The resin layer includes sulfur.

Abstract: To provide a highly flexible display device excellent in mass-productivity. A display device includes a flexible substrate, an adhesive layer over the substrate, a resin layer over the adhesive layer, an inorganic insulating layer over the resin layer, a transistor over the inorganic insulating layer, and a display element electrically connected to the transistor. The transistor includes an oxide semiconductor in a channel formation region. The resin layer includes sulfur.

Abstract: A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Abstract: The semiconductor device includes an oxide semiconductor; a source electrode and a drain electrode in contact with the oxide semiconductor; a gate insulating film over the oxide semiconductor, the source electrode, and the drain electrode; and a gate electrode overlapping the oxide semiconductor, part of the source electrode, and part of the drain electrode with the gate insulating film positioned therebetween. The source electrode and the drain electrode each include a Cu—X alloy film (X is Mn, Ni, Cr, Fe, Co, Mo, Ta, or Ti), and the thickness of a region of the oxide semiconductor over which neither the source electrode nor the drain electrode is provided is smaller than the thicknesses of regions of the oxide semiconductor over which the source electrode and the drain electrode are provided.

Abstract: A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Abstract: To provide a highly flexible display device excellent in mass-productivity. A display device includes a flexible substrate, an adhesive layer over the substrate, a resin layer over the adhesive layer, an inorganic insulating layer over the resin layer, a transistor over the inorganic insulating layer, and a display element electrically connected to the transistor. The transistor includes an oxide semiconductor in a channel formation region. The resin layer includes sulfur.

Abstract: To provide a highly reliable semiconductor device which includes a transistor including an oxide semiconductor, in a semiconductor device including a staggered transistor having a bottom-gate structure provided over a glass substrate, a gate insulating film in which a first gate insulating film and a second gate insulating film, whose compositions are different from each other, are stacked in this order is provided over a gate electrode layer. Alternatively, in a staggered transistor having a bottom-gate structure, a protective insulating film is provided between a glass substrate and a gate electrode layer. A metal element contained in the glass substrate has a concentration lower than or equal to 5×1018 atoms/cm3 at the interface between the first gate insulating film and the second gate insulating film or the interface between the gate electrode layer and a gate insulating film.

Abstract: A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Abstract: A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Abstract: A semiconductor device includes a gate electrode; a gate insulating film over the gate electrode; an oxide semiconductor film in contact with the gate insulating film and including a channel formation region which overlaps with the gate electrode; a source electrode and a drain electrode over the oxide semiconductor film; and an oxide insulating film over the oxide semiconductor film, the source electrode, and the drain electrode. The source electrode and the drain electrode each include a first metal film having an end portion at the end of the channel formation region, a second metal film over the first metal film and containing copper, and a third metal film over the second metal film. The second metal film is formed on the inner side than the end portion of the first metal film.

Abstract: A method for manufacturing a semiconductor device includes the steps of forming a first conductive film over a substrate; forming an insulating film over the first conductive film; forming an oxide semiconductor film over the insulating film to overlap with the first conductive film; forming a second conductive film including a metal film containing molybdenum as its main component and a metal film containing copper as its main component over the oxide semiconductor film; and etching the second conductive film by an etchant. At the time of etching the second conductive film by the etchant, the oxide semiconductor film is used as an etching stopper film. In addition, the etchant which can be used for a transistor including the oxide semiconductor film is provided.