Abstract: An image display device includes a first substrate; a second substrate located to face the first substrate; an electro-optical layer between the first substrate and the second substrate; a plurality of pixel electrodes located between the electro-optical layer and the first substrate; a plurality of switching elements electrically connected with the plurality of pixel electrodes respectively; and a color filter included in a layer between the first substrate and the plurality of switching elements. A side of the first substrate opposite to a side thereof facing the electro-optical layer is an image display side.

Abstract: An object is to provide a semiconductor device including an oxynitride semiconductor whose carrier density is controlled. By introducing controlled nitrogen into an oxide semiconductor layer, a transistor in which an oxynitride semiconductor having desired carrier density and on characteristics is used for a channel can be manufactured. Further, with the use of the oxynitride semiconductor, even when a low resistance layer or the like is not provided between an oxynitride semiconductor layer and a source electrode and between the oxynitride semiconductor layer and a drain electrode, favorable contact characteristics can be exhibited.

Abstract: In a semiconductor device including an oxide semiconductor, the amount of oxygen vacancies is reduced. Moreover, electrical characteristics of a semiconductor device including an oxide semiconductor are improved. The semiconductor device includes a transistor including a gate electrode over a substrate, a gate insulating film covering the gate electrode, an oxide semiconductor film overlapping with the gate electrode with the gate insulating film provided therebetween, and a pair of electrodes in contact with the oxide semiconductor film; and over the transistor, a first insulating film covering the gate insulating film, the oxide semiconductor film, and the pair of electrodes; and a second insulating film covering the first insulating film. An etching rate of the first insulating film is lower than or equal to 10 nm/min and lower than an etching rate of the second insulating film when etching is performed at 25° C. with 0.5 weight % of hydrofluoric acid.

Abstract: An object is to provide a high reliable semiconductor device including a thin film transistor having stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (which is for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor film and reduce impurities such as moisture. Besides impurities such as moisture existing in the oxide semiconductor film, heat treatment causes reduction of impurities such as moisture existing in the gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor film and are in contact with the oxide semiconductor film.

Abstract: A semiconductor device is manufactured using a transistor in which an oxide semiconductor is included in a channel region and variation in electric characteristics due to a short-channel effect is less likely to be caused. The semiconductor device includes an oxide semiconductor film having a pair of oxynitride semiconductor regions including nitrogen and an oxide semiconductor region sandwiched between the pair of oxynitride semiconductor regions, a gate insulating film, and a gate electrode provided over the oxide semiconductor region with the gate insulating film positioned therebetween. Here, the pair of oxynitride semiconductor regions serves as a source region and a drain region of the transistor, and the oxide semiconductor region serves as the channel region of the transistor.

Abstract: It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided.

Abstract: An object is to control composition and a defect of an oxide semiconductor, another object is to increase a field effect mobility of a thin film transistor and to obtain a sufficient on-off ratio with a reduced off current. A solution is to employ an oxide semiconductor whose composition is represented by InMO3(ZnO)m, where M is one or a plurality of elements selected from Ga, Fe, Ni, Mn, Co, and Al, and m is preferably a non-integer number of greater than 0 and less than 1. The concentration of Zn is lower than the concentrations of In and M. The oxide semiconductor has an amorphous structure. Oxide and nitride layers can be provided to prevent pollution and degradation of the oxide semiconductor.

Abstract: In a transistor including an oxide semiconductor film, movement of hydrogen and nitrogen to the oxide semiconductor film is suppressed. Further, in a semiconductor device using a transistor including an oxide semiconductor film, a change in electrical characteristics is suppressed and reliability is improved. A transistor including an oxide semiconductor film and a nitride insulating film provided over the transistor are included, and an amount of hydrogen molecules released from the nitride insulating film by thermal desorption spectroscopy is less than 5×1021 molecules/cm3, preferably less than or equal to 3×1021 molecules/cm3, more preferably less than or equal to 1×1021 molecules/cm3, and an amount of ammonia molecules released from the nitride insulating film by thermal desorption spectroscopy is less than 1×1022 molecules/cm3, preferably less than or equal to 5×1021 molecules/cm3, more preferably less than or equal to 1×1021 molecules/cm3.

Abstract: A display device including a pixel having a memory. The pixel includes at least a display element, a capacitor, an inverter, and a switch. The switch is controlled with a signal held in the capacitor and a signal output from the inverter so that voltage is supplied to the display element. The inverter and the switch can be constituted by transistors with the same polarity. A semiconductor layer included in the pixel may be formed using a light-transmitting material. Moreover, a gate electrode, a drain electrode, and a capacitor electrode may be formed using a light-transmitting conductive layer. The pixel is formed using a light-transmitting material in such a manner, whereby the display device can be a transmissive display device while including a pixel having a memory.

Abstract: A semiconductor device including a substrate, a first insulating layer above the substrate, a first transistor including a first oxide semiconductor layer above the first insulating layer, and a second transistor including a second oxide semiconductor layer above the first insulating layer, a composition of the second oxide semiconductor layer being different from a composition of the first oxide semiconductor layer.

Abstract: In a semiconductor device including a transistor including a gate electrode formed over a substrate, a gate insulating film covering the gate electrode, a multilayer film overlapping with the gate electrode with the gate insulating film provided therebetween, and a pair of electrodes in contact with the multilayer film, a first oxide insulating film covering the transistor, and a second oxide insulating film formed over the first oxide insulating film, the multilayer film includes an oxide semiconductor film and an oxide film containing In or Ga, the oxide semiconductor film has an amorphous structure or a microcrystalline structure, the first oxide insulating film is an oxide insulating film through which oxygen is permeated, and the second oxide insulating film is an oxide insulating film containing more oxygen than that in the stoichiometric composition.

Abstract: In a semiconductor device including a transistor including an oxide semiconductor film and a protective film over the transistor, an oxide insulating film containing oxygen in excess of the stoichiometric composition is formed as the protective film under the following conditions: a substrate placed in a treatment chamber evacuated to a vacuum level is held at a temperature higher than or equal to 180° C. and lower than or equal to 260° C.; a source gas is introduced into the treatment chamber so that the pressure in the treatment chamber is set to be higher than or equal to 100 Pa and lower than or equal to 250 Pa; and a high-frequency power higher than or equal to 0.17 W/cm2 and lower than or equal to 0.5 W/cm2 is supplied to an electrode provided in the treatment chamber.

Abstract: An object is to manufacture a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (for dehydration or dehydrogenation) is performed to improve the purity of the oxide semiconductor film and reduce impurities including moisture or the like. After that, slow cooling is performed under an oxygen atmosphere. Besides impurities including moisture or the like exiting in the oxide semiconductor film, heat treatment causes reduction of impurities including moisture or the like exiting in a gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor and in contact therewith.

Abstract: A method for manufacturing an oxide semiconductor layer, comprising forming an oxide semiconductor layer over an insulating layer so as to be along with a curved surface of a projecting structural body of the insulating layer, wherein a length of the projecting structural body in a height direction is larger than a width of the projecting structural body, is provided.

Abstract: An object is to provide a high reliable semiconductor device including a thin film transistor having stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (which is for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor film and reduce impurities such as moisture. Besides impurities such as moisture existing in the oxide semiconductor film, heat treatment causes reduction of impurities such as moisture existing in the gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor film and are in contact with the oxide semiconductor film.

Abstract: It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another obj ect to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer having a channel formation region, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer and reduce impurities such as moisture. Moreover, the oxide semiconductor layer subjected to the heat treatment is slowly cooled under an oxygen atmosphere.

Abstract: A semiconductor device including a first oxide insulating layer, a barrier layer above the first oxide insulating layer, the barrier layer including an opening, a second oxide insulating layer above the first oxide insulating layer at a position overlapping the opening, an oxide semiconductor layer facing the first oxide insulating layer interposed by the second oxide insulating layer at a position overlapping the opening, a gate electrode facing the oxide semiconductor layer at side opposite to the first oxide insulating layer with respect to the oxide semiconductor layer, and a gate insulating layer between the oxide semiconductor layer and the gate electrode. A contained amount of oxygen in the first oxide insulating layer is larger than a contained amount of oxygen in the second oxide insulating layer.

Abstract: An object is to manufacture a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (for dehydration or dehydrogenation) is performed to improve the purity of the oxide semiconductor film and reduce impurities including moisture or the like. After that, slow cooling is performed under an oxygen atmosphere. Besides impurities including moisture or the like exiting in the oxide semiconductor film, heat treatment causes reduction of impurities including moisture or the like exiting in a gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor and in contact therewith.

Abstract: An object is to improve field effect mobility of a thin film transistor using an oxide semiconductor. Another object is to suppress increase in off current even in a thin film transistor with improved field effect mobility. In a thin film transistor using an oxide semiconductor layer, by forming a semiconductor layer having higher electrical conductivity and a smaller thickness than the oxide semiconductor layer between the oxide semiconductor layer and a gate insulating layer, field effect mobility of the thin film transistor can be improved, and increase in off current can be suppressed.

Abstract: To provide a highly reliable semiconductor device manufactured by giving stable electric characteristics to a semiconductor device including an oxide semiconductor. In a manufacturing process of a transistor, an oxide semiconductor layer, a source electrode layer, a drain electrode layer, a gate insulating film, a gate electrode layer, and an aluminum oxide film are formed in this order, and then heat treatment is performed on the oxide semiconductor layer and the aluminum oxide film, whereby an oxide semiconductor layer from which an impurity containing a hydrogen atom is removed and which includes a region containing oxygen more than the stoichiometric proportion is formed. In addition, when the aluminum oxide film is formed, entry and diffusion of water or hydrogen into the oxide semiconductor layer from the air due to heat treatment in a manufacturing process of a semiconductor device or an electronic appliance including the transistor can be prevented.