摘要:
An oxide semiconductor stacked film which does not easily cause a variation in electrical characteristics of a transistor and has high stability is provided. Further, a transistor which includes the oxide semiconductor stacked film in its channel formation region and has stable electrical characteristics is provided. An oxide semiconductor stacked film includes a first oxide semiconductor layer, a second oxide semiconductor layer, and a third oxide semiconductor layer which are sequentially stacked and each of which contains indium, gallium, and zinc. The content percentage of indium in the second oxide semiconductor layer is higher than that in the first oxide semiconductor layer and the third oxide semiconductor layer, and the absorption coefficient of the oxide semiconductor stacked film, which is measured by the CPM, is lower than or equal to 3×10−3/cm in an energy range of 1.5 eV to 2.3 eV.
摘要:
An objet of the present invention is to provide a semiconductor device with a new structure. Disclosed is a semiconductor device including a first transistor which includes a channel formation region on a substrate containing a semiconductor material, impurity regions formed with the channel formation region interposed therebetween, a first gate insulating layer over the channel formation region, a first gate electrode over the first gate insulating layer, and a first source electrode and a first drain electrode which are electrically connected to the impurity region; and a second transistor which includes a second gate electrode over the substrate containing a semiconductor material, a second gate insulating layer over the second gate electrode, an oxide semiconductor layer over the second gate insulating layer, and a second source electrode and a second drain electrode which are electrically connected to the oxide semiconductor layer.
摘要:
A logic circuit includes a thin film transistor having a channel formation region formed using an oxide semiconductor, and a capacitor having terminals one of which is brought into a floating state by turning off the thin film transistor. The oxide semiconductor has a hydrogen concentration of 5×1019 (atoms/cm3) or less and thus substantially serves as an insulator in a state where an electric field is not generated. Therefore, off-state current of a thin film transistor can be reduced, leading to suppressing the leakage of electric charge stored in a capacitor, through the thin film transistor. Accordingly, a malfunction of the logic circuit can be prevented. Further, the excessive amount of current which flows in the logic circuit can be reduced through the reduction of off-state current of the thin film transistor, resulting in low power consumption of the logic circuit.
摘要:
It is an object to provide a semiconductor device in which power consumption can be reduced. It is another object to provide a highly reliable semiconductor device using a programming cell, such as a programmable logic device (PLD). In accordance with a change in a configuration of connections between basic blocks, power supply voltage furnishing to the basic blocks is changed. That is, when the structure of connections between the basic blocks is such that a basic block does not contribute to a circuit, the supply of the power supply voltage to this basic block is stopped. Further, the supply of the power supply voltage to the basic blocks is controlled using a programming cell formed using a field effect transistor whose channel formation region is formed using an oxide semiconductor, the field effect transistor having extremely low off-state current or extremely low leakage current.
摘要:
The invention provides a transistor comprising a gate electrode layer; a gate insulating layer over the gate electrode layer; an oxide semiconductor layer over the gate insulating layer; and an oxide insulating layer over and in contact with the oxide semiconductor layer, wherein the oxide semiconductor layer includes indium, zinc, and one or more metal elements selected from gallium, aluminum, manganese, cobalt and tin; and wherein a region of the oxide semiconductor layer is formed of microcrystals c-axis-oriented in a direction perpendicular to a surface of the oxide semiconductor layer.
摘要:
A manufacturing method of a display device having TFTs capable of high-speed operation with few variations of threshold voltage is provided, in which materials are used with high efficiency and a small number of photomasks is required. The display device of the invention comprises a gate electrode layer (103) and a pixel electrode layer (120) formed over an insulating surface (100), a gate insulating layer (105) formed over the gate electrode layer (103), a crystalline semiconductor layer (107) formed over the gate insulating layer (105), a semiconductor layer having one conductivity type (109) formed in contact with the crystalline semiconductor layer (107), a source electrode layer (114) and a drain electrode layer (115) formed in contact with the semiconductor layer having one conductivity type (109), an insulating layer (140) formed over the source electrode layer (114), the drain electrode layer (115), and the pixel electrode layer (120), a first opening (138) formed in the insulating layer (140) to reach the source electrode layer (114) or the drain electrode layer (115), a second opening (139) formed in the gate insulating layer (105) and the insulating layer (140) to reach the pixel electrode layer (120), and a wiring layer (119) formed in the first opening (138) and the second opening (139) to electrically connect the source electrode layer (114) or the drain electrode layer (115) to the pixel electrode layer (120).
摘要:
To reduce power consumption and suppress display degradation of a liquid crystal display device. To suppress display degradation due to an external factor such as temperature. A transistor whose channel formation region is formed using an oxide semiconductor layer is used for a transistor provided in each pixel. Note that with the use of a high-purity oxide semiconductor layer, off-state current of the transistor at a room temperature can be 10 aA/μm or less and off-state current at 85° C. can be 100 aA/μm or less. Consequently, power consumption of a liquid crystal display device can be reduced and display degradation can be suppressed. Further, as described above, off-state current of the transistor at a temperature as high as 85° C. can be 100 aA/μm or less. Thus, display degradation of a liquid crystal display device due to an external factor such as temperature can be suppressed.