A method for making an array substrate includes the following steps: forming a poly-silicon semiconductor layer on a substrate; forming a buffer layer on the substrate; depositing a first metal layer, and patterning the first metal layer to form gate electrodes for a driving TFT, a switch TFT, and a poly-silicon TFT; forming a first gate insulator layer; forming a second gate insulator layer; defining through holes passing through the buffer layer, the first gate insulator layer, and the second gate insulator layer to expose the poly-silicon semiconductor layer; depositing a metal oxide layer to form a first metal oxide semiconductor layer; and depositing a second metal layer to form source electrodes and drain electrodes for the driving TFT, the switch TFT, and the poly-silicon TFT.

A method of manufacturing, with high mass productivity, liquid crystal display devices having highly reliable thin film transistors with excellent electric characteristics is provided. In a liquid crystal display device having an inverted staggered thin film transistor, the inverted staggered thin film transistor is formed as follows: a gate insulating film is formed over a gate electrode; a microcrystalline semiconductor film which functions as a channel formation region is formed over the gate insulating film; a buffer layer is formed over the microcrystalline semiconductor film; a pair of source and drain regions are formed over the buffer layer; and a pair of source and drain electrodes are formed in contact with the source and drain regions so as to expose a part of the source and drain regions.

An oxide semiconductor layer which is intrinsic or substantially intrinsic and includes a crystalline region in a surface portion of the oxide semiconductor layer is used for the transistors. An intrinsic or substantially intrinsic semiconductor from which an impurity which is to be an electron donor (donor) is removed from an oxide semiconductor and which has a larger energy gap than a silicon semiconductor is used. Electrical characteristics of the transistors can be controlled by controlling the potential of a pair of conductive films which are provided on opposite sides from each other with respect to the oxide semiconductor layer, each with an insulating film arranged therebetween, so that the position of a channel formed in the oxide semiconductor layer is determined.

An object of the invention is to improve the reliability of a light-emitting device. Another object of the invention is to provide flexibility to a light-emitting device having a thin film transistor using an oxide semiconductor film. A light-emitting device has, over one flexible substrate, a driving circuit portion including a thin film transistor for a driving circuit and a pixel portion including a thin film transistor for a pixel. The thin film transistor for a driving circuit and the thin film transistor for a pixel are inverted staggered thin film transistors including an oxide semiconductor layer which is in contact with a part of an oxide insulating layer.

A transistor device and method of making the same, the transistor device including: a substrate; a word line disposed on the substrate; a gate insulating layer disposed on the word line; a dual-layer semiconductor channel including: a first channel layer disposed on the gate insulating layer; and a second channel layer disposed on the first channel layer, such that the second channel layer contacts side and top surfaces of the first channel layer; and source and drain electrodes electrically coupled to the second channel layer. When a voltage is applied to the word line, the first channel layer has a first electrical resistance and the second channel layer has a second electrical resistance that is different from the first electrical resistance.

The present invention provides a microstructure in which evenly distributed crystal grains line up in parallel lines extending along the surface of the film, and a no-lateral-growth region left at each of locations exposed to both ends of a grain interface, which serves as a partition between the neighboring two crystal grains. According to the present invention, there are also provided: a method for forming a polycrystalline film, such as a thin polycrystalline silicon film, a thin aluminum film, and a thin copper film, which is flat and even, in surface, electrically uniform and stable, and mechanically stable; a laser crystallization device for use in manufacture of polycrystalline films, and a semiconductor device using the polycrystalline film and having good electrical property and increased breakdown voltage.

An electronic device including a first substrate, a semiconductor layer, a second substrate and a color filter is disclosed. The first substrate has a peripheral region. The semiconductor layer is disposed on the first substrate in the peripheral region. The second substrate is opposite to the first substrate. The color filter is disposed between the first substrate and the second substrate and in the peripheral region of the first substrate, and the color filter overlaps the semiconductor layer.

A method of producing a reduced-defect density crystalline silicon film includes forming a first intrinsic silicon film on a substrate, forming a doped film including silicon or germanium on the first intrinsic silicon film, forming a second intrinsic silicon film on the doped film, and annealing to crystallize the doped film, the second intrinsic silicon film, and the first intrinsic silicon, wherein each film is amorphous at formation, wherein crystallization initiates within the doped film. A method of forming a thin film transistor includes forming an active layer in the crystallized second intrinsic silicon layer by doping the crystallized second intrinsic silicon layer in selected areas to form source and drain regions separated by a channel portion, forming a gate insulator layer on the crystallized second intrinsic silicon layer, and forming a gate electrode pattern over the gate insulator layer.

A liquid crystal display device according to FFS technology is provided, which sufficiently provides a common electrode with common electric potential and improves an aperture ratio of pixels. A pixel electrode is formed of a first layer transparent electrode. A common electrode made of a second layer transparent electrode is formed above the pixel electrode interposing an insulation film between them. The common electrode in an upper layer is provided with a plurality of slits. The common electrode extends over all the pixels in a display region. An end of the common electrode is disposed on a periphery of the display region and connected with a peripheral common electric potential line that provides a common electric potential Vcom. There is provided neither an auxiliary common electrode line nor a pad electrode, both of which are provided in a liquid crystal display device according to a conventional art.

A liquid crystal display device according to FFS technology is provided, which sufficiently provides a common electrode with common electric potential and improves an aperture ratio of pixels. A pixel electrode is formed of a first layer transparent electrode. A common electrode made of a second layer transparent electrode is formed above the pixel electrode interposing an insulation film between them. The common electrode in an upper layer is provided with a plurality of slits. The common electrode extends over all the pixels in a display region. An end of the common electrode is disposed on a periphery of the display region and connected with a peripheral common electric potential line that provides a common electric potential Vcom. There is provided neither an auxiliary common electrode line nor a pad electrode, both of which are provided in a liquid crystal display device according to a conventional art.