摘要:
A microcrystalline semiconductor film having a high crystallinity is formed. Further, a thin film transistor having preferable electric characteristics and high reliability and a display device including the thin film transistor are manufactured with high mass productivity. A step in which a deposition gas containing silicon or germanium is introduced at a first flow rate and a step in which the deposition gas containing silicon or germanium is introduced at a second flow rate are repeated while hydrogen is introduced at a fixed rate, so that the hydrogen and the deposition gas containing silicon or germanium are mixed, and a high-frequency power is supplied. Therefore, a microcrystalline semiconductor film is formed over a substrate.
摘要:
A plasma treatment apparatus includes a treatment chamber covered with a chamber wall, where an upper electrode faces a lower electrode; and a line chamber separated from the treatment chamber by the upper electrode and an insulator, covered with the chamber wall, and connected to a first gas diffusion chamber between a dispersion plate and a shower plate. The first gas diffusion chamber is connected to a second gas diffusion chamber between the dispersion plate and the upper electrode. The second gas diffusion chamber is connected to a first gas pipe in the upper electrode. The upper electrode and the chamber wall are provided on the same axis. The dispersion plate includes a center portion with no gas hole and a peripheral portion with plural gas holes. The center portion faces a gas introduction port of the first gas pipe, connected to an electrode plane of the upper electrode.
摘要:
An object is to provide a thin film transistor with small off current, large on current, and high field-effect mobility. A silicon nitride layer and a silicon oxide layer which is formed by oxidizing the silicon nitride layer are stacked as a gate insulating layer, and crystals grow from an interface of the silicon oxide layer of the gate insulating layer to form a microcrystalline semiconductor layer; thus, an inverted staggered thin film transistor is manufactured. Since crystals grow from the gate insulating layer, the thin film transistor can have a high crystallinity, large on current, and high field-effect mobility. In addition, a buffer layer is provided to reduce off current.
摘要:
An object is to provide a method for manufacturing a thin film transistor having favorable electric characteristics, with high productivity. A gate electrode is formed over a substrate and a gate insulating layer is formed over the gate electrode. A first semiconductor layer is formed over the gate insulating layer by generating plasma using a deposition gas containing silicon or germanium, hydrogen, and a rare gas. Next, a second semiconductor layer including an amorphous semiconductor and a microcrystal semiconductor is formed in such a manner that the first semiconductor layer is partially grown as a seed crystal by generating plasma using a deposition gas containing silicon or germanium, hydrogen, and a gas containing nitrogen. Then, a semiconductor layer to which an impurity imparting one conductivity is added is formed and a conductive film is formed. Thus, a thin film transistor is manufactured.
摘要:
A highly reliable transistor in which change in electrical characteristics is suppressed is provided. A highly reliable transistor in which change in electrical characteristics is suppressed is manufactured with high productivity. A display device with less image deterioration over time is provided. An inverted staggered thin film transistor which includes, between a gate insulating film and impurity semiconductor films functioning as source and drain regions, a semiconductor stacked body including a microcrystalline semiconductor region and a pair of amorphous semiconductor regions. In the microcrystalline semiconductor region, the nitrogen concentration on the gate insulating film side is low and the nitrogen concentration in a region in contact with the amorphous semiconductor is high. Further, an interface with the amorphous semiconductor has unevenness.
摘要:
Provided is a method for manufacturing a semiconductor device, in which a degradation of characteristics of a thin film transistor can be suppressed by performing plasma oxidation treatment on a gate insulating film containing nitrogen. An embodiment of the present invention is a method for manufacturing a semiconductor device comprising a thin film transistor including a gate electrode, a gate insulating film containing nitrogen, and a channel region in microcrystalline semiconductor films. The method includes the steps of performing plasma treatment on the gate insulating film in an oxidizing gas atmosphere containing hydrogen and an oxidizing gas containing an oxygen atom, and forming the microcrystalline semiconductor film over the gate insulating film. Formula (1), a/b≧2, and Formula (2), b>0, are satisfied, where the amount of hydrogen and the amount of the oxidizing gas in the oxidizing gas atmosphere are a and b, respectively.
摘要:
A display device of which frame can be narrowed and of which display characteristics are excellent is provided. In a display device including a switch portion or a buffer portion, a logic circuit portion, and a pixel portion, the pixel portion includes a first inverted staggered TFT and a pixel electrode which is connected to a wiring of the first inverted staggered TFT, the switch portion or the buffer portion includes a second inverted staggered TFT in which a first insulating layer, a semiconductor layer, and a second insulating layer are interposed between a first gate electrode and a second gate electrode, the logic circuit portion includes an inverter circuit including a third inverted staggered thin film transistor and a fourth inverted staggered thin film transistor, and the first to the fourth inverted staggered thin film transistors have the same polarity. The inverter circuit may be an EDMOS circuit.
摘要:
An object is to prevent light leakage caused due to misregistration even when the width of a black matrix layer is not expanded to a designed value or larger. One embodiment of the present invention is a semiconductor device including a single-gate thin film transistor in which a first semiconductor layer is sandwiched between a bottom-gate electrode and a first black matrix layer. The first semiconductor layer and the first black matrix layer overlap with each other.
摘要:
An object is to provide a novel structure of a backlight unit using color-scan backlight drive, which can relieve a color mixture problem. A backlight unit including a plurality of light guide elements is used. The light guide element has a shape extended in the x direction. The light guide element has a shape of rectangular column. Grooves are provided on a bottom surface of the light guide element so as to traverse it in the y direction. Light sources are provided at the ends of the light guide element in the x direction to supply light into the light guide element. Light supplied into the light guide element is reflected by the grooves in the z direction, and emitted to the outside of the light guide element through the top surface. A reflective layer may be provided under the bottom surface of the light guide element.
摘要:
A space is provided under part of a semiconductor layer. Specifically, a structure in which an eaves portion (a projecting portion, an overhang portion) is formed in the semiconductor layer. The eaves portion is formed as follows: a stacked-layer structure in which a conductive layer, an insulating layer, and a semiconductor layer are stacked in this order is etched collectively to determine a pattern of a gate electrode; and a pattern of the semiconductor layer is formed while side-etching is performed.