An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

There is provided a light emitting device in which low power consumption can be realized even in the case of a large screen. The surface of a source signal line or a power supply line in a pixel portion is plated to reduce a resistance of a wiring. The source signal line in the pixel portion is manufactured by a step different from a source signal line in a driver circuit portion. The power supply line in the pixel portion is manufactured by a step different from a power supply line led on a substrate. A terminal is similarly plated to made the resistance reduction. It is desirable that a wiring before plating is made of the same material as a gate electrode and the surface of the wiring is plated to form the source signal line or the power supply line.

Light emitting device and method of manufacturing the same

To prevent a point defect and a line defect in forming a light-emitting device, thereby improving the yield. A light-emitting element and a driver circuit of the light-emitting element, which are provided over different substrates, are electrically connected. That is, a light-emitting element and a driver circuit of the light-emitting element are formed over different substrates first, and then electrically connected. By providing a light-emitting element and a driver circuit of the light-emitting element over different substrates, the step of forming the light-emitting element and the step of forming the driver circuit of the light-emitting element can be performed separately. Therefore, degrees of freedom of each step can be increased, and the process can be flexibly changed. Further, steps (irregularities) on the surface for forming the light-emitting element can be reduced than in the conventional technique.

Light-emitting device and manufacturing method thereof

A gate-insulated thin film transistor is disclosed. One improvement is that the thin film transistor is formed on a substrate through a blocking layer in between so that it is possible to prevent the transistor from being contaminated with impurities such as alkali ions which exist in the substrate. Also, a halogen is added to either or both of the blocking layer and a gate insulator of the transistor in order that impurities such as alkaline ions, dangling bonds and the like can be neutralized, therefore, the reliability of the device is improved.

Thin-film transistor

An active layer of an NTFT includes a channel forming region, at least a first impurity region, at least a second impurity region and at least a third impurity region therein. Concentrations of an impurity in each of the first, second and third impurity regions increase as distances from the channel forming region become longer. The first impurity region is formed to be overlapped with a side wall. A gate overlapping structure can be realized with the side wall functioning as an electrode.

Semiconductor device and manufacturing method therefor

High performance low temperature polycrystalline silicon (poly-Si) thin film transistors (TFTs) with large grains were created using diode pumped solid state (DPSS) continuous wave (CW) laser lateral crystallization (CLC), employing fabrication processes at 450°C. Field-effect mobilities of 566 cm2/Vs for the n-channel and 200 cm2/Vs for the p-channel were obtained for a thick Si film (100–150 nm) on a 300×300 mm non-alkaline glass substrate. The high performance of the TFTs is attributed to the predominantly (100)-oriented very large grains. With a decreasing Si-film thickness, the grain size decreases, and the surface orientation of the grain changes from (100) to other orientations. These effects lead to reduced field-effect mobility with decreasing Si-film thickness, but it is easy to obtain a high field-effect mobility of over 300 cm2/Vs, even with a 50 nm thick Si film, without special processing techniques. A complementary metal oxide semiconductor (CMOS) ring oscillator was fabricated using a thin Si film 65 nm thick to demonstrate the high circuit performance of CLC poly-Si TFTs by applying the simplest CMOS process technology. A delay of 400 ps/stage at a gate length of 1.5 µm and a supply voltage of Vdd=5.0 (V) was produced on a large non-alkaline glass substrate utilizing a fabrication temperature of 450°C. This crystallization method will lead to the fabrication of high-performance and cheap Si-LSI circuits on large non-alkaline glass substrates.

High Performance Low Temperature Polycrystalline Silicon Thin Film Transistors on Non-alkaline Glass Produced Using Diode Pumped Solid State Continuous Wave Laser Lateral Crystallization

We have developed high performance poly-Si TFTs, which have comparable performance to that of [100] Si-MOSFETs, by using a stable scanning DPSS CW laser lateral crystallization without introduction of thermal damage to 300/spl times/300 mm/sup 2/ glass substrates with process temperature below 450/spl deg/C.

High performance poly-Si TFTs on a glass by a stable scanning CW laser lateral crystallization

A power supply voltage booster avoids inadequate step-up capability. In a voltage boosting circuit, a switching device connects and disconnects between the ground potential and one end of the coil, the other end of which is supplied with a supply voltage VB. The switching device is repeatedly turned ON and OFF such that the capacitor is electrically charged from the force in the coil when the switching device is turned off. A charging control circuit turns off the switching device when current flowing through the switching device into the coil is determined to have increased to a switch-off threshold value when the switching device is ON, and turns on the switching device upon determining that the charging current flowing to the capacitor from the coil decreases to a switch-on threshold value when the switching device is OFF. The charging control circuit sets the switch-off threshold value to a larger value as the supply voltage VB is lower. Thus, inadequacy of the step-up capability caused by a drop in the supply voltage VB can be avoided.

Power supply voltage booster

A method of manufacturing a semiconductor device according to the present invention includes a process of introducing impurities into a semiconductor layer with a gate electrode and a resist film as a mask after a resist film is formed on the top and the side of the gate electrode by soaking the gate electrode on a semiconductor layer in an electrolyte containing resist and applying voltage to the gate electrode

Method of manufacturing thin film transistors in a liquid crystal display

Using an ultrahigh‐vacuum (UHV) sputtering system, we could grow two new methods of polycrystalline silicon films. The one is as‐deposited polycrystalline silicon on glass at substrate temperatures under 500 °C. The other is solid‐phase‐crystallization by thermal annealing of as‐deposited amorphous silicon films in a UHV. As‐deposited polycrystalline silicon films were oriented to (220) and grain sizes were determined from half‐width of x‐ray diffraction to be about 40 nm. From the deposition temperature dependence of the x‐ray diffraction peak intensity, the activation energy of the crystalline growth was calculated to be about 0.6 eV. Hydrogen atoms in the sputtering gas lower the reproducibility of as‐deposited poly‐Si. Polycrystalline silicon films produced by thermal annealing of as‐deposited amorphous silicon films at 550 °C in UHV have a (111) orientation. Field‐effect mobilities of the as‐deposited polycrystalline silicon film and the polycrystalline silicon film by UHV thermal annealing were 5 an...

Tatsuya Kakehi

Papers

High Performance Low Temperature Polycrystalline Silicon Thin Film Transistors on Non-alkaline Glass Produced Using Diode Pumped Solid State Continuous Wave Laser Lateral Crystallization

High performance poly-Si TFTs on a glass by a stable scanning CW laser lateral crystallization

Power supply voltage booster

Method of manufacturing thin film transistors in a liquid crystal display

Polycrystalline silicon formed by ultrahigh‐vacuum sputtering system