Abstract: As a display device has a higher definition, the number of pixels, gate lines, and signal lines are increased. When the number of the gate lines and the signal lines are increased, a problem of higher manufacturing cost, because it is difficult to mount an IC chip including a driver circuit for driving of the gate and signal lines by bonding or the like. A pixel portion and a driver circuit for driving the pixel portion are provided over the same substrate, and at least part of the driver circuit includes a thin film transistor using an oxide semiconductor interposed between gate electrodes provided above and below the oxide semiconductor. Therefore, when the pixel portion and the driver portion are provided over the same substrate, manufacturing cost can be reduced.

Abstract: A wiring having excellent electrical characteristics is provided. A wiring having stable electrical characteristics is provided. A device is manufactured through the steps of forming a first insulating film over a substrate, forming a second insulating film over the first insulating film, removing part of the first insulating film and part of the second insulating film to form a first opening, forming a first conductor in the first opening and over a top surface of the second insulating film, and forming a second conductor by planarizing a surface of the first conductor so as to remove part of the first conductor.

Abstract: As a display device has higher definition, the number of pixels is increased and thus, the number of gate lines and signal lines is increased. When the number of gate lines and signal lines is increased, it is difficult to mount IC chips including driver circuits for driving the gate lines and the signal lines by bonding or the like, whereby manufacturing cost is increased. A pixel portion and a driver circuit for driving the pixel portion are provided on the same substrate, and at least part of the driver circuit comprises a thin film transistor including an oxide semiconductor sandwiched between gate electrodes. A channel protective layer is provided between the oxide semiconductor and a gate electrode provided over the oxide semiconductor. The pixel portion and the driver circuit are provided on the same substrate, which leads to reduction of manufacturing cost.

Abstract: To offer a semiconductor device including a thin film transistor having excellent characteristics and high reliability and a method for manufacturing the semiconductor device without variation. The summary is to include an inverted-staggered (bottom-gate structure) thin film transistor in which an oxide semiconductor film containing In, Ga, and Zn is used for a semiconductor layer and a buffer layer is provided between the semiconductor layer and source and drain electrode layers. An ohmic contact is formed by intentionally providing a buffer layer containing In, Ga, and Zn and having a higher carrier concentration than the semiconductor layer between the semiconductor layer and the source and drain electrode layers.

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 production system using a laser crystallization method is provided which can avoid forming grain boundaries in a channel formation region of a TFT, thereby preventing grain boundaries from lowering the mobility of the TFT greatly, from lowering ON current, and from increasing OFF current. Rectangular or stripe pattern depression and projection portions are formed on an insulating film. A semiconductor film is formed on the insulating film. The semiconductor film is irradiated with continuous wave laser light by running the laser light along the stripe pattern depression and projection portions of the insulating film or along the major or minor axis direction of the rectangle. Although continuous wave laser light is most preferred among laser light, it is also possible to use pulse oscillation laser light in irradiating the semiconductor film.

Abstract: As a display device has higher definition, the number of pixels is increased and thus, the number of gate lines and signal lines is increased. When the number of gate lines and signal lines is increased, it is difficult to mount IC chips including driver circuits for driving the gate lines and the signal lines by bonding or the like, whereby manufacturing cost is increased. A pixel portion and a driver circuit for driving the pixel portion are provided on the same substrate, and at least part of the driver circuit comprises a thin film transistor including an oxide semiconductor sandwiched between gate electrodes. A channel protective layer is provided between the oxide semiconductor and a gate electrode provided over the oxide semiconductor. The pixel portion and the driver circuit are provided on the same substrate, which leads to reduction of manufacturing cost.

Abstract: To offer a semiconductor device including a thin film transistor having excellent characteristics and high reliability and a method for manufacturing the semiconductor device without variation. The summary is to include an inverted-staggered (bottom-gate structure) thin film transistor in which an oxide semiconductor film containing In, Ga, and Zn is used for a semiconductor layer and a buffer layer is provided between the semiconductor layer and source and drain electrode layers. An ohmic contact is formed by intentionally providing a buffer layer containing In, Ga, and Zn and having a higher carrier concentration than the semiconductor layer between the semiconductor layer and the source and drain electrode layers.

Abstract: A semiconductor device production system using a laser crystallization method is provided which can avoid forming grain boundaries in a channel formation region of a TFT, thereby preventing grain boundaries from lowering the mobility of the TFT greatly, from lowering ON current, and from increasing OFF current. Rectangular or stripe pattern depression and projection portions are formed on an insulating film. A semiconductor film is formed on the insulating film. The semiconductor film is irradiated with continuous wave laser light by running the laser light along the stripe pattern depression and projection portions of the insulating film or along the major or minor axis direction of the rectangle. Although continuous wave laser light is most preferred among laser light, it is also possible to use pulse oscillation laser light in irradiating the semiconductor film.

Abstract: The present invention is characterized in that by laser beam being slantly incident to the convex lens, an aberration such as astigmatism or the like is occurred, and the shape of the laser beam is made linear on the irradiation surface or in its neighborhood. Since the present invention has a very simple configuration, the optical adjustment is easier, and the device becomes compact in size. Furthermore, since the beam is slantly incident with respect to the irradiated body, the return beam can be prevented.

Abstract: A semiconductor device production system using a laser crystallization method is provided which can avoid forming grain boundaries in a channel formation region of a TFT, thereby preventing grain boundaries from lowering the mobility of the TFT greatly, from lowering ON current, and from increasing OFF current. Rectangular or stripe pattern depression and projection portions are formed on an insulating film. A semiconductor film is formed on the insulating film. The semiconductor film is irradiated with continuous wave laser light by running the laser light along the stripe pattern depression and projection portions of the insulating film or along the major or minor axis direction of the rectangle. Although continuous wave laser light is most preferred among laser light, it is also possible to use pulse oscillation laser light in irradiating the semiconductor film.

Abstract: A novel semiconductor device or memory device is provided. Alternatively, a semiconductor device or memory device in which storage capacity per unit area is large is provided. The semiconductor device includes a sense amplifier provided to a semiconductor substrate and a memory cell provided over the sense amplifier. The sense amplifier includes a first transistor. The memory cell includes a capacitor over the semiconductor substrate, a second transistor provided over the capacitor, a conductor, and a groove portion. The capacitor includes a first electrode and a second electrode. The first electrode is formed along the groove portion. The second electrode has a region facing the first electrode in the groove portion. The second transistor includes an oxide semiconductor. One of a source and a drain of the second transistor is electrically connected to the second electrode through the conductor.

Abstract: The present invention is characterized in that by laser beam being slantly incident to the convex lens, an aberration such as astigmatism or the like is occurred, and the shape of the laser beam is made linear on the irradiation surface or in its neighborhood. Since the present invention has a very simple configuration, the optical adjustment is easier, and the device becomes compact in size. Furthermore, since the beam is slantly incident with respect to the irradiated body, the return beam can be prevented.

Abstract: A semiconductor device production system using a laser crystallization method is provided which can avoid forming grain boundaries in a channel formulation region of a TFT, thereby preventing grain boundaries from lowering the mobility of the TFT greatly, from lowering ON current, and from increasing OFF current. Rectangular or stripe pattern depression and projection portions are formed on an insulating film. A semiconductor film is formed on the insulating film. The semiconductor film is irradiated with continuous wave laser light by running the laser light along the stripe pattern depression and projection portions of the insulating film or along the major or minor axis direction of the rectangle. Although continuous wave laser light is most preferred among laser light, it is also possible to use pulse oscillation laser light in irradiating the semiconductor film.

Abstract: To provide a semiconductor device including a thin film transistor having excellent electric characteristics and high reliability and a manufacturing method of the semiconductor device with high mass productivity. The summary is that an inverted-staggered (bottom-gate) thin film transistor is included in which an oxide semiconductor film containing In, Ga, and Zn is used as a semiconductor layer, a channel protective layer is provided in a region that overlaps a channel formation region of the semiconductor layer, and a buffer layer is provided between the semiconductor layer and source and drain electrodes. An ohmic contact is formed by intentionally providing the buffer layer having a higher carrier concentration than the semiconductor layer between the semiconductor layer and the source and drain electrodes.

Abstract: An embodiment is to include an inverted staggered (bottom gate structure) thin film transistor in which an oxide semiconductor film containing In, Ga, and Zn is used as a semiconductor layer and a buffer layer is provided between the semiconductor layer and a source and drain electrode layers. The buffer layer having higher carrier concentration than the semiconductor layer is provided intentionally between the source and drain electrode layers and the semiconductor layer, whereby an ohmic contact is formed.

Abstract: As a display device has higher definition, the number of pixels is increased and thus, the number of gate lines and signal lines is increased. When the number of gate lines and signal lines is increased, it is difficult to mount IC chips including driver circuits for driving the gate lines and the signal lines by bonding or the like, whereby manufacturing cost is increased. A pixel portion and a driver circuit for driving the pixel portion are provided on the same substrate, and at least part of the driver circuit comprises a thin film transistor including an oxide semiconductor sandwiched between gate electrodes. A channel protective layer is provided between the oxide semiconductor and a gate electrode provided over the oxide semiconductor. The pixel portion and the driver circuit are provided on the same substrate, which leads to reduction of manufacturing cost.

Abstract: As a display device has higher definition, the number of pixels is increased and thus, the number of gate lines and signal lines is increased. When the number of gate lines and signal lines is increased, it is difficult to mount IC chips including driver circuits for driving the gate lines and the signal lines by bonding or the like, whereby manufacturing cost is increased. A pixel portion and a driver circuit for driving the pixel portion are provided on the same substrate, and at least part of the driver circuit comprises a thin film transistor including an oxide semiconductor sandwiched between gate electrodes. A channel protective layer is provided between the oxide semiconductor and a gate electrode provided over the oxide semiconductor. The pixel portion and the driver circuit are provided on the same substrate, which leads to reduction of manufacturing cost.

Abstract: Provided is a semiconductor device that occupies a small area, a highly integrated semiconductor device, or a semiconductor device with high productivity. To fabricate an integrated circuit, a first insulating film is formed over a p-channel transistor; a transistor including an oxide semiconductor is formed over the first insulating film; a second insulating film is formed over the transistor; an opening, that is, a contact hole part of a sidewall of which is formed of the oxide semiconductor of the transistor, is formed in the first insulating film and the second insulating film; and an electrode connecting the p-channel transistor and the transistor including an oxide semiconductor to each other is formed.

Abstract: As a display device has a higher definition, the number of pixels, gate lines, and signal lines are increased. When the number of the gate lines and the signal lines are increased, a problem of higher manufacturing cost, because it is difficult to mount an IC chip including a driver circuit for driving of the gate and signal lines by bonding or the like. A pixel portion and a driver circuit for driving the pixel portion are provided over the same substrate, and at least part of the driver circuit includes a thin film transistor using an oxide semiconductor interposed between gate electrodes provided above and below the oxide semiconductor. Therefore, when the pixel portion and the driver portion are provided over the same substrate, manufacturing cost can be reduced.