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: The present invention provides a method for manufacturing a highly reliable display device at a low cost with high yield. According to the present invention, a step due to an opening in a contact is covered with an insulating layer to reduce the step, and is processed into a gentle shape. A wiring or the like is formed to be in contact with the insulating layer and thus the coverage of the wiring or the like is enhanced. In addition, deterioration of a light-emitting element due to contaminants such as water can be prevented by sealing a layer including an organic material that has water permeability in a display device with a sealing material. Since the sealing material is formed in a portion of a driver circuit region in the display device, the frame margin of the display device can be narrowed.

Abstract: To provide a highly reliable semiconductor device using an oxide semiconductor. The semiconductor device includes a first electrode layer; a second electrode layer positioned over the first electrode layer and including a stacked-layer structure of a first conductive layer and a second conductive layer; and an oxide semiconductor film and an insulating film positioned between the first electrode layer and the second electrode layer in a thickness direction. The first conductive layer and the insulating film have a first opening portion in a region overlapping with the first electrode layer. The oxide semiconductor film has a second opening portion in a region overlapping with the first opening portion. The second conductive layer is in contact with the first electrode layer exposed in the first opening portion and the second opening portion.

Abstract: A semiconductor device which includes a transistor having a miniaturized structure is provided. A first insulator is provided over a stack in which a semiconductor, a first conductor, and a second conductor are stacked in this order. Over the first insulator, an etching mask is formed. Using the etching mask, the first insulator and the second conductor are etched until the first conductor is exposed. After etching the first conductor until the semiconductor is exposed so as to form a groove having a smaller width than the second conductor, a second insulator and a third conductor are formed sequentially.

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 minute transistor is provided. A transistor with small parasitic capacitance is provided. A transistor with high frequency characteristics is provided. A semiconductor device including the transistor is provided. A semiconductor device includes an oxide semiconductor, a first conductor and a second insulator embedded in a first insulator, a second conductor and a third conductor. Edges of the second conductor and the third conductor facing each other each has a taper angle of 30 degree or more and 90 degree or less.

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: The present invention provides a method for manufacturing a highly reliable display device at a low cost with high yield. According to the present invention, a step due to an opening in a contact is covered with an insulating layer to reduce the step, and is processed into a gentle shape. A wiring or the like is formed to be in contact with the insulating layer and thus the coverage of the wiring or the like is enhanced. In addition, deterioration of a light-emitting element due to contaminants such as water can be prevented by sealing a layer including an organic material that has water permeability in a display device with a sealing material. Since the sealing material is formed in a portion of a driver circuit region in the display device, the frame margin of the display device can be narrowed.

Abstract: When an oxide semiconductor film is microfabricated, with the use of a hard mask, unevenness of a side surface of the oxide semiconductor film can be suppressed. Specifically, a semiconductor device comprises an oxide semiconductor film over an insulating surface; a first hard mask and a second hard mask over the oxide semiconductor film; a source electrode over the oxide semiconductor film and the first hard mask; a drain electrode over the oxide semiconductor film and the second hard mask; a gate insulating film over the source electrode and the drain electrode; and a gate electrode overlapping with the gate insulating film and the oxide semiconductor film, and the first and second hard masks have conductivity.

Abstract: A semiconductor device that occupies a small area and has a high degree of integration is provided. The semiconductor device includes a first insulating layer, a conductive layer, and a second insulating layer. The conductive layer is between the first insulating layer and the second insulating layer. The first insulating layer, the conductive layer, and the second insulating layer overlap with each other in a region. A contact plug penetrates the first insulating layer, the conductive layer, and the second insulating layer. In a depth direction from the second insulating layer to the first insulating layer, a diameter of the contact plug changes to a smaller value at an interface between the second insulating layer and the conductive layer.

Abstract: It is an object to reduce defective conduction in a wiring board or a semiconductor device whose integration degree is increased. It is another object to manufacture a highly reliable wiring board or semiconductor device with high yield. In a wiring board or a semiconductor device having a multilayer wiring structure, a conductive layer having a curved surface is used in connection between conductive layers used for the wirings. The top of a conductive layer in a lower layer exposed by removal of an insulating layer therearound has a curved surface, so that coverage of the conductive layer in the lower layer with a conductive layer in an upper layer stacked thereover can be favorable. A conductive layer is etched using a resist mask having a curved surface, so that a conductive layer having a curved surface is formed.

Abstract: To give favorable electrical characteristics to a semiconductor device. The semiconductor device includes an insulating layer, a semiconductor layer over the insulating layer, a pair of electrodes over the semiconductor layer and each electrically connected to the semiconductor layer, a gate electrode over the semiconductor layer, and a gate insulating layer between the semiconductor layer and the gate electrode. The insulating layer includes an island-shaped projecting portion. A top surface of the projecting portion of the insulating layer is in contact with a bottom surface of the semiconductor layer, and is positioned on an inner side of the semiconductor layer when seen from above. The pair of electrodes covers part of a top surface and part of side surfaces of the semiconductor layer. Furthermore, the gate electrode and the gate insulating layer cover side surfaces of the projecting portion of the insulating layer.

Abstract: A minute transistor is provided. A transistor having low parasitic capacitance is provided. A transistor having high frequency characteristics is provided. An electrode including the transistor is provided. A novel electrode is provided. The electrode includes a first conductive layer containing a metal, an insulating layer, and a second conductive layer. The insulating layer is formed over the first conductive layer. A mask layer is formed over the insulating layer. The insulating layer is etched using plasma with the mask layer used as a mask, whereby an opening is formed in the insulating layer so as to reach the first conductive layer. Plasma treatment is performed on at least the opening in an oxygen atmosphere. By the plasma treatment, a metal-containing oxide is formed on the first conductive layer in the opening. The oxide is removed, and then the second conductive layer is formed in the opening.

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 a first opening, a second opening, and a third opening which are formed by performing first etching and second etching. By the first etching, the first insulator is etched for forming the first opening, the second opening, and the third opening. By the second etching, the first metal oxide, the second insulator, the third insulator, the fourth insulator, the second metal oxide, and the fifth insulator are etched for forming the first opening; the first metal oxide, the second insulator, and the third insulator are etched for forming the second opening; and the first metal oxide is etched for forming the third opening.

Abstract: A substrate having an insulating surface is prepared; a stacked film including a first oxide semiconductor layer and a second oxide semiconductor layer is formed over the substrate; a mask layer is formed over part of the stacked film and then dry etching treatment is performed, so that the stacked film is removed, with a region provided with the mask layer remaining, and a reaction product is formed on a side surface of the remaining stacked film; the reaction product is removed by wet etching treatment after removal of the mask layer; a source electrode and a drain electrode are formed over the stacked film; and a third oxide semiconductor layer, a gate insulating film, and a gate electrode are stacked and formed in this order over the stacked film, and the source electrode and the drain electrode.

Abstract: To provide a semiconductor device which occupies a small area and is highly integrated. A first conductive layer is formed; a first insulating layer is formed over the first conductive layer; a second conductive layer is formed over the first insulating layer using the same material as the first conductive layer; a third conductive layer is formed over the second conductive layer; a second insulating layer is formed over the third conductive layer; a resist mask is formed over the second insulating layer; etching is successively performed from the upper layer and an opening is formed in the first conductive layer and the diameter of the opening in the second conductive layer is increased in the same step; and a contact hole where an upper surface of the first conductive layer is exposed is formed by etching the first insulating layer.

Abstract: It is an object to reduce defective conduction in a wiring board or a semiconductor device whose integration degree is increased. It is another object to manufacture a highly reliable wiring board or semiconductor device with high yield. In a wiring board or a semiconductor device having a multilayer wiring structure, a conductive layer having a curved surface is used in connection between conductive layers used for the wirings. The top of a conductive layer in a lower layer exposed by removal of an insulating layer therearound has a curved surface, so that coverage of the conductive layer in the lower layer with a conductive layer in an upper layer stacked thereover can be favorable. A conductive layer is etched using a resist mask having a curved surface, so that a conductive layer having a curved surface is formed.

Abstract: When an oxide semiconductor film is microfabricated, with the use of a hard mask, unevenness of a side surface of the oxide semiconductor film can be suppressed. Specifically, a semiconductor device comprises an oxide semiconductor film over an insulating surface; a first hard mask and a second hard mask over the oxide semiconductor film; a source electrode over the oxide semiconductor film and the first hard mask; a drain electrode over the oxide semiconductor film and the second hard mask; a gate insulating film over the source electrode and the drain electrode; and a gate electrode overlapping with the gate insulating film and the oxide semiconductor film, and the first and second hard masks have conductivity.

Abstract: A miniaturized transistor having high electric characteristics is provided with high yield. In a semiconductor device including the transistor, high performance, high reliability, and high productivity are achieved. In a semiconductor device including a transistor in which an oxide semiconductor film, a gate insulating film, and a gate electrode layer on side surfaces of which sidewall insulating layers are provided are stacked in this order, source and drain electrode layers are provided in contact with the oxide semiconductor film and the sidewall insulating layers. In a process for manufacturing the semiconductor device, a conductive film and an interlayer insulating film are stacked to cover the oxide semiconductor film, the sidewall insulating layers, and the gate electrode layer, and the interlayer insulating film and the conductive film over the gate electrode layer are removed by a chemical mechanical polishing method, so that the source and drain electrode layers are formed.

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.