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 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 semiconductor device with favorable reliability is provided. The semiconductor device includes a first insulator; a second insulator positioned over the first insulator; an oxide positioned over the second insulator; a first conductor and a second conductor positioned apart from each other over the oxide; a third insulator positioned over the oxide, the first conductor, and the second conductor; a third conductor positioned over the third insulator and at least partly overlapping with a region between the first conductor and the second conductor; a fourth insulator positioned to cover the oxide, the first conductor, the second conductor, the third insulator, and the third conductor; a fifth insulator positioned over the fourth insulator; and a sixth insulator positioned over the fifth insulator.

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 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 with excellent electric characteristics is provided. The semiconductor device includes an oxide in a channel formation region. The semiconductor device includes the oxide over a substrate, a first insulator over the oxide, a second insulator over the first insulator, a third insulator, and a conductor over the third insulator. The oxide and the first insulator are in contact with each other in a region. An opening exposing the oxide is provided in the first insulator and the second insulator. The third insulator is placed to cover an inner wall and a bottom surface of the opening. The conductor is placed to fill the opening. The conductor has a region overlapping with the oxide with the third insulator between the conductor and the oxide. The first insulator contains an element other than a main component of the oxide.

Abstract: First to third insulators are successively formed in this order over a first conductor over a semiconductor substrate; a hard mask with a first opening is formed thereover; a resist mask with a second opening is formed thereover; a third opening is formed in the third insulator; a fourth opening is formed in the second insulator; the resist mask is removed; a fifth opening is formed in the first to third insulators; a second conductor is formed to cover an inner wall and a bottom surface of the fifth opening; a third conductor is formed thereover; polishing treatment is performed so that the hard mask is removed, and that levels of top surfaces of the second and third conductors and the third insulator are substantially equal to each other; and an oxide semiconductor is formed thereover. The second insulator is less permeable to hydrogen than the first and third insulators, the second conductor is less permeable to hydrogen than the third conductor.

Abstract: First to third insulators are successively formed in this order over a first conductor over a semiconductor substrate; a hard mask with a first opening is formed thereover; a resist mask with a second opening is formed thereover; a third opening is formed in the third insulator; a fourth opening is formed in the second insulator; the resist mask is removed; a fifth opening is formed in the first to third insulators; a second conductor is formed to cover an inner wall and a bottom surface of the fifth opening; a third conductor is formed thereover; polishing treatment is performed so that the hard mask is removed, and that levels of top surfaces of the second and third conductors and the third insulator are substantially equal to each other; and an oxide semiconductor is formed thereover. The second insulator is less permeable to hydrogen than the first and third insulators, the second conductor is less permeable to hydrogen than the third conductor.

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 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: 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 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: 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 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 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 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: A semiconductor device for miniaturization is provided. The semiconductor device includes a semiconductor layer; a first electrode and a second electrode that are on the semiconductor layer and apart from each other over the semiconductor layer; a gate electrode over the semiconductor layer; and a gate insulating layer between the semiconductor layer and the gate electrode. The first and second electrodes comprise first conductive layers and second conductive layers. In a region overlapping with the semiconductor layer, the second conductive layers are positioned between the first conductive layers, and side surfaces of the second conductive layers are in contact with side surfaces of the first conductive layers. The second conductive layers have smaller thicknesses than those of the first conductive layers, and the top surface levels of the second conductive layers are lower than those of the first conductive layers.

Abstract: First to third insulators are successively formed in this order over a first conductor over a semiconductor substrate; a hard mask with a first opening is formed thereover; a resist mask with a second opening is formed thereover; a third opening is formed in the third insulator; a fourth opening is formed in the second insulator; the resist mask is removed; a fifth opening is formed in the first to third insulators; a second conductor is formed to cover an inner wall and a bottom surface of the fifth opening; a third conductor is formed thereover; polishing treatment is performed so that the hard mask is removed, and that levels of top surfaces of the second and third conductors and the third insulator are substantially equal to each other; and an oxide semiconductor is formed thereover. The second insulator is less permeable to hydrogen than the first and third insulators, the second conductor is less permeable to hydrogen than the third conductor.