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Patent

Amorphous oxide and thin film transistor

TL;DR: In this paper, an amorphous oxide and a thin-film transistor were constructed using an electron carrier concentration less than 10 18 /cm 3, where the electron carrier was obtained by using a gate electrode and gate insulating film.
Abstract: The present invention relates to an amorphous oxide and a thin film transistor using the amorphous oxide. In particular, the present invention provides an amorphous oxide having an electron carrier concentration less than 10 18 /cm 3 , and a thin film transistor using such an amorphous oxide. In a thin film transistor having a source electrode 6 , a drain electrode 5 , a gate electrode 4 , a gate insulating film 3 , and a channel layer 2 , an amorphous oxide having an electron carrier concentration less than 10 18 /cm 3 is used in the channel layer 2.
Citations
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Patent
18 May 2006
TL;DR: In this paper, a light-emitting device with the use of an amorphous oxide was presented, which has a lightemitting layer existing between first and second electrodes and a field effect transistor, of which the active layer is an Amorphous.
Abstract: An object of the present invention is to provide a new light-emitting device with the use of an amorphous oxide. The light-emitting device has a light-emitting layer existing between first and second electrodes and a field effect transistor, of which the active layer is an amorphous.

1,551 citations

Patent
01 Aug 2008
TL;DR: In this article, the oxide semiconductor film has at least a crystallized region in a channel region, which is defined as a region of interest (ROI) for a semiconductor device.
Abstract: 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.

1,501 citations

Patent
09 Nov 2005
TL;DR: In this paper, a field-effect transistor with an active layer and a gate insulating film is presented, where the active layer includes an amorphous oxide layer and the gate insulator.
Abstract: Provided is a field-effect transistor including an active layer and a gate insulating film, wherein the active layer includes an amorphous oxide layer containing an amorphous region and a crystalline region, and the crystalline region is in the vicinity of or in contact with an interface between the amorphous oxide layer and the gate insulating film

1,320 citations

Patent
09 Nov 2005
TL;DR: In this article, a novel amorphous oxide applicable to an active layer of a TFT is provided, which consists of microcrystals and can be applied to any TFT.
Abstract: A novel amorphous oxide applicable, for example, to an active layer of a TFT is provided. The amorphous oxide comprises microcrystals.

1,182 citations

Patent
25 Sep 2013
TL;DR: In this paper, a connection terminal portion is provided with a plurality of connection pads which are part of the connection terminal, each of which includes a first connection pad and a second connection pad having a line width different from that of the first one.
Abstract: An object of the present invention is to decrease the resistance of a power supply line, to suppress a voltage drop in the power supply line, and to prevent defective display. A connection terminal portion includes a plurality of connection terminals. The plurality of connection terminals is provided with a plurality of connection pads which is part of the connection terminal. The plurality of connection pads includes a first connection pad and a second connection pad having a line width different from that of the first connection pad. Pitches between the plurality of connection pads are equal to each other.

1,136 citations

References
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Journal ArticleDOI
25 Nov 2004-Nature
TL;DR: A novel semiconducting material is proposed—namely, a transparent amorphous oxide semiconductor from the In-Ga-Zn-O system (a-IGZO)—for the active channel in transparent thin-film transistors (TTFTs), which are fabricated on polyethylene terephthalate sheets and exhibit saturation mobilities and device characteristics are stable during repetitive bending of the TTFT sheet.
Abstract: Transparent electronic devices formed on flexible substrates are expected to meet emerging technological demands where silicon-based electronics cannot provide a solution. Examples of active flexible applications include paper displays and wearable computers1. So far, mainly flexible devices based on hydrogenated amorphous silicon (a-Si:H)2,3,4,5 and organic semiconductors2,6,7,8,9,10 have been investigated. However, the performance of these devices has been insufficient for use as transistors in practical computers and current-driven organic light-emitting diode displays. Fabricating high-performance devices is challenging, owing to a trade-off between processing temperature and device performance. Here, we propose to solve this problem by using a novel semiconducting material—namely, a transparent amorphous oxide semiconductor from the In-Ga-Zn-O system (a-IGZO)—for the active channel in transparent thin-film transistors (TTFTs). The a-IGZO is deposited on polyethylene terephthalate at room temperature and exhibits Hall effect mobilities exceeding 10 cm2 V-1 s-1, which is an order of magnitude larger than for hydrogenated amorphous silicon. TTFTs fabricated on polyethylene terephthalate sheets exhibit saturation mobilities of 6–9 cm2 V-1 s-1, and device characteristics are stable during repetitive bending of the TTFT sheet.

7,301 citations

Journal ArticleDOI
23 May 2003-Science
TL;DR: The fabrication of transparent field-effect transistors using a single-crystalline thin-film transparent oxide semiconductor, InGaO3(ZnO)5, as an electron channel and amorphous hafnium oxide as a gate insulator provides a step toward the realization of transparent electronics for next-generation optoelectronics.
Abstract: We report the fabrication of transparent field-effect transistors using a single-crystalline thin-film transparent oxide semiconductor, InGaO 3 (ZnO) 5 , as an electron channel and amorphous hafnium oxide as a gate insulator. The device exhibits an on-to-off current ratio of ∼10 6 and a field-effect mobility of ∼80 square centimeters per volt per second at room temperature, with operation insensitive to visible light irradiation. The result provides a step toward the realization of transparent electronics for next-generation optoelectronics.

2,724 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed a transparent ZnO-based thin-film transistors (TFTs) for select-transistors in each pixel of an active-matrix liquid-crystal display.
Abstract: Highly transparent ZnO-based thin-film transistors (TFTs) are fabricated with optical transmission (including substrate) of ∼75% in the visible portion of the electromagnetic spectrum. Current–voltage measurements indicate n-channel, enhancement-mode TFT operation with excellent drain current saturation and a drain current on-to-off ratio of ∼107. Threshold voltages and channel mobilities of devices fabricated to date range from ∼10 to 20 V and ∼0.3 to 2.5 cm2/V s, respectively. Exposure to ambient light has little to no observable effect on the drain current. In contrast, exposure to intense ultraviolet radiation results in persistent photoconductivity, associated with the creation of electron-hole pairs by ultraviolet photons with energies greater than the ZnO band gap. Light sensitivity is reduced by decreasing the ZnO channel layer thickness. One attractive application for transparent TFTs involves their use as select-transistors in each pixel of an active-matrix liquid-crystal display.

1,415 citations

Journal ArticleDOI
TL;DR: In this paper, a field-effect transistor made of transparant oxidic thin films, showing an intrinsic memory function due to the usage of a ferroelectric insulator.
Abstract: Operation is demonstrated of a field‐effect transistor made of transparant oxidic thin films, showing an intrinsic memory function due to the usage of a ferroelectric insulator. The device consists of a high mobility Sb‐doped n‐type SnO2 semiconductor layer, PbZr0.2Ti0.8O3 as a ferroelectric insulator, and SrRuO3 as a gate electrode, each layer prepared by pulsed laser deposition. The hysteresis behavior of the channel conductance is studied. Using gate voltage pulses of 100 μs duration and a pulse height of ±3 V, a change of a factor of two in the remnant conductance is achieved. The dependence of the conductance on the polarity of the gate pulse proves that the memory effect is driven by the ferroelectric polarization. The influence of charge trapping is also observed and discussed.

1,175 citations

Patent
21 Aug 2002
TL;DR: In this article, a thin-film transistor with a transparent semiconductor film is proposed, and the oxide is formed of the oxide to restrain a material for the second layer from depriving oxygen of the semiconductor layer.
Abstract: In a thin film transistor, a gate insulating film having a first insulating film and a second insulating film is formed on a gate electrode, and a semiconductor layer including ZnO etc. is formed on the second insulating film. The first insulating film is formed by using SiN x having a high insulating characteristic, and the second insulating film is formed by using an oxide (for example, SiO 2 ). This structure improves a crystalline characteristic of the semiconductor layer that constitutes an interface in combination with the second insulating film, and decreases a defective level of the interface between the semiconductor layer and the second insulating film. Further, the second insulating film is constituted of the oxide, so that it is possible to restrain a material for the second insulating film from depriving oxygen of the semiconductor layer. This keeps a crystalline characteristic of the semiconductor layer under a preferable condition in the vicinity of the interface between the second insulating film and the semiconductor layer. As a result, it is possible to realize a thin film transistor such that: a leak current level at an OFF area is low, and the mobility is high, and a switching characteristic is preferable. Thus, in the thin film transistor having a transparent semiconductor film, a TFT characteristic is improved.

1,154 citations