Abstract: To provide a method by which a semiconductor device including a thin film transistor with excellent electric characteristics and high reliability is manufactured with a small number of steps. After a channel protective layer is formed over an oxide semiconductor film containing In, Ga, and Zn, a film having n-type conductivity and a conductive film are formed, and a resist mask is formed over the conductive film. The conductive film, the film having n-type conductivity, and the oxide semiconductor film containing In, Ga, and Zn are etched using the channel protective layer and gate insulating films as etching stoppers with the resist mask, so that source and drain electrode layers, a buffer layer, and a semiconductor layer are formed.

Abstract: A protective circuit includes a non-linear element, which further includes a gate electrode, a gate insulating layer covering the gate electrode, a pair of first and second wiring layers whose end portions overlap with the gate electrode over the gate insulating layer and in which a conductive layer and a second oxide semiconductor layer are stacked, and a first oxide semiconductor layer which overlaps with at least the gate electrode and which is in contact with side face portions of the gate insulating layer and the conductive layer of the first wiring layer and the second wiring layer and a side face portion and a top face portion of the second oxide semiconductor layer. Over the gate insulating layer, oxide semiconductor layers with different properties are bonded to each other, whereby stable operation can be performed as compared with Schottky junction. Thus, the junction leakage can be decreased and the characteristics of the non-linear element can be improved.

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: An oxide semiconductor film which has more stable electric conductivity is provided. The oxide semiconductor film comprises a crystalline region. The oxide semiconductor film has a first peak of electron diffraction intensity with a full width at half maximum of greater than or equal to 0.4 nm?1 and less than or equal to 0.7 nm?1 in a region where a magnitude of a scattering vector is greater than or equal to 3.3 nm?1 and less than or equal to 4.1 nm?1. The oxide semiconductor film has a second peak of electron diffraction intensity with a full width at half maximum of greater than or equal to 0.45 nm?1 and less than or equal to 1.4 nm?1 in a region where a magnitude of a scattering vector is greater than or equal to 5.5 nm?1 and less than or equal to 7.1 nm?1.

Abstract: It is an object of the present invention to provide a technique for manufacturing a highly reliable display device at low cost with high yield. A first electrode layer is formed by a sputtering method using a gas containing hydrogen or H2O, an electroluminescent layer is formed over the first electrode layer, and a second electrode layer is formed over the electroluminescent layer. According to one aspect of the present invention, a display device is manufactured to include a first electrode layer including indium zinc oxide containing silicon oxide and tungsten oxide, an electroluminescent layer over the first electrode layer, and a second electrode layer over the electroluminescent layer, where the electroluminescent layer includes a layer containing an organic compound and an inorganic compound to be in contact with the first electrode layer.

Abstract: In an active matrix display device, electric characteristics of thin film transistors included in a circuit are important, and performance of the display device depends on the electric characteristics. Thus, by using an oxide semiconductor film including In, Ga, and Zn for an inverted staggered thin film transistor, variation in electric characteristics of the thin film transistor can be reduced. Three layers of a gate insulating film, an oxide semiconductor layer and a channel protective layer are successively formed by a sputtering method without being exposed to air. Further, in the oxide semiconductor layer, the thickness of a region overlapping with the channel protective film is larger than that of a region in contact with a conductive film.

Abstract: In a channel protected thin film transistor in which a channel formation region is formed using an oxide semiconductor, an oxide semiconductor layer which is dehydrated or dehydrogenated by a heat treatment is used as an active layer, a crystal region including nanocrystals is included in a superficial portion in the channel formation region, and the rest portion is amorphous or is formed of a mixture of amorphousness/non-crystals and microcrystals, where an amorphous region is dotted with microcrystals. By using an oxide semiconductor layer having such a structure, a change to an n-type caused by entry of moisture or elimination of oxygen to or from the superficial portion and generation of a parasitic channel can be prevented and a contact resistance with a source and drain electrodes can be reduced.

Abstract: It is an object to provide a highly reliable semiconductor device with good electrical characteristics and a display device including the semiconductor device as a switching element. In a transistor including an oxide semiconductor layer, a needle crystal group provided on at least one surface side of the oxide semiconductor layer grows in a c-axis direction perpendicular to the surface and includes an a-b plane parallel to the surface, and a portion except for the needle crystal group is an amorphous region or a region in which amorphousness and microcrystals are mixed. Accordingly, a highly reliable semiconductor device with good electrical characteristics can be formed.

Abstract: A pixel portion and a driver circuit driving the pixel portion are formed over the same substrate. At least a part of the driver circuit is formed using an inverted staggered thin film transistor in which an oxide semiconductor layer is used and a channel protective layer is provided over the oxide semiconductor layer serving as a channel formation region which is overlapped with the gate electrode. The driver circuit as well as the pixel portion is provided over the same substrate to reduce manufacturing costs.

Abstract: A thin film transistor structure in which a source electrode and a drain electrode formed from a metal material are in direct contact with an oxide semiconductor film may lead to high contact resistance. One cause of high contact resistance is that a Schottky junction is formed at a contact plane between the source and drain electrodes and the oxide semiconductor film. An oxygen-deficient oxide semiconductor layer which includes crystal grains with a size of 1 nm to 10 nm and has a higher carrier concentration than the oxide semiconductor film serving as a channel formation region is provided between the oxide semiconductor film and the source and drain electrodes.

Abstract: To manufacture a highly reliable semiconductor device by giving stable electric characteristics to a transistor. An oxide semiconductor film is deposited by a sputtering method with the use of a polycrystalline sputtering target. In that case, partial pressure of water in a deposition chamber before or in the deposition is set to be lower than or equal to 10?3 Pa, preferably lower than or equal to 10?4 Pa, more preferably lower than or equal to 10?5 Pa. Thus, a dense oxide semiconductor film is obtained. The density of the oxide semiconductor film is higher than 6.0 g/cm3 and lower than 6.375 g/cm3.

Abstract: A structure by which electric-field concentration which might occur between a source electrode and a drain electrode in a bottom-gate thin film transistor is relaxed and deterioration of the switching characteristics is suppressed, and a manufacturing method thereof. A bottom-gate thin film transistor in which an oxide semiconductor layer is provided over a source and drain electrodes is manufactured, and angle ?1 of the side surface of the source electrode which is in contact with the oxide semiconductor layer and angle ?2 of the side surface of the drain electrode which is in contact with the oxide semiconductor layer are each set to be greater than or equal to 20° and less than 90°, so that the distance from the top edge to the bottom edge in the side surface of each electrode is increased.

Abstract: A display device includes a pixel portion in which a pixel electrode layer is arranged in a matrix, and an inverted staggered thin film transistor having a combination of at least two kinds of oxide semiconductor layers with different amounts of oxygen is provided corresponding to the pixel electrode layer. In the periphery of the pixel portion in this display device, a pad portion is provided to be electrically connected to a common electrode layer formed on a counter substrate through a conductive layer made of the same material as the pixel electrode layer. One objection of our invention to prevent a defect due to separation of a thin film in various kinds of display devices is realized, by providing a structure suitable for a pad portion provided in a display panel.

Abstract: There are provided microorganisms having a property of producing a lipid containing unsaturated fatty acids as constituent fatty acids and extracellularly secreting the produced lipid encapsulated in lipid particles, methods of screening said microorganisms, as well as methods of efficiently producing a fatty acid-containing lipid using said microorganisms. Furthermore, there are provided lipid particles encapsulating a lipid containing unsaturated fatty acids, and foods, cosmetics, and animal feeds comprising said lipid particles added thereto. Artificially treated microorganisms or microorganisms collected from nature are grown on a solid medium, and microbial strains that form lipid particles at the periphery of the colonies and/or microbial strains that, when cultured in a transparent liquid medium, make the culture liquid cloudy are selected.

Abstract: To provide an imaging device that is highly stable when exposed to radiation such as X-rays. The imaging device includes a substrate, a pixel circuit, and a scintillator which are stacked in order. The pixel circuit includes a light-receiving element and a circuit portion electrically connected to the light-receiving element. The substrate is provided with a heater. A transistor in the pixel circuit is heated by the passage of a current through the heater at times other than imaging, thus, degradation of the electrical characteristics of the transistor due to X-ray irradiation can be recovered.

Abstract: An object of the present invention is to provide a method for manufacturing a thin film transistor which enables heat treatment aimed at improving characteristics of a gate insulating film such as lowering of an interface level or reduction in a fixed charge without causing a problem of misalignment in patterning due to expansion or shrinkage of glass. A method for manufacturing a thin film transistor of the present invention comprises the steps of heat-treating in a state where at least a gate insulating film is formed over a semiconductor film on which element isolation is not performed, simultaneously isolating the gate insulating film and the semiconductor film into an element structure, forming an insulating film covering a side face of an exposed semiconductor film, thereby preventing a short-circuit between the semiconductor film and a gate electrode.

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: 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: An object is to provide a semiconductor device including an oxide semiconductor film, which has stable electrical characteristics and high reliability. A stack of first and second material films is formed by forming the first material film (a film having a hexagonal crystal structure) having a thickness of 1 nm to 10 nm over an insulating surface and forming the second material film having a hexagonal crystal structure (a crystalline oxide semiconductor film) using the first material film as a nucleus. As the first material film, a material film having a wurtzite crystal structure (e.g., gallium nitride or aluminum nitride) or a material film having a corundum crystal structure (?-Al2O3, ?-Ga2O3, In2O3, Ti2O3, V2O3, Cr2O3, or ?-Fe2O3) is used.

Abstract: An imaging device which is highly stable to irradiation with radiations such as X-rays and can inhibit a decrease in electrical characteristics is provided. The imaging device obtains an image using radiations such as X-rays and includes pixel circuits which are arranged in a matrix and which a scintillator overlaps. Each of the pixel circuits includes a switching transistor whose off-state current is extremely low and a light-receiving element. A shielding layer formed using a metal material and the like overlaps the transistor and the light-receiving element. With the structure, an imaging device which is highly stable to irradiation with radiations such as X-rays and can inhibit a decrease in electrical characteristics can be provided.