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Myung Kwan Ryu

Bio: Myung Kwan Ryu is an academic researcher from Samsung. The author has contributed to research in topics: Thin-film transistor & Threshold voltage. The author has an hindex of 18, co-authored 39 publications receiving 3075 citations.

Papers
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Journal ArticleDOI
01 May 2008
TL;DR: In this paper, GIZO TFTs with high mobility of 2.6 cm2/Vs and threshold voltage standard deviation of 0.7V which is comparable to that of a-Si TFT are fabricated.
Abstract: We successfully fabricated GIZO (Ga2O3-In2O3-ZnO) TFTs with high mobility of 2.6 cm2/Vs and threshold voltage standard deviation of 0.7V which is comparable to that of a-Si TFTs. Because conventional 5 mask process and bottom gate TFT structure of back channel etch type with channel length of 5 μm is used, it is expected to be transferred to mass production line in near future. Also we report the dependency of threshold voltage on the post process after the back surface of GIZO is exposed and suggest the effective method for controlling the threshold voltage of amorphous GIZO TFTs. Finally we demonstrate 4 inch QVGA AMOLED display driven by GIZO TFTs.

990 citations

Proceedings ArticleDOI
01 Dec 2009
TL;DR: In this paper, a self-aligned top-gate amorphous oxide TFTs for large size and high resolution displays are presented, where Ar plasma is exposed on the source/drain region of active layer to minimize the source and drain series resistances.
Abstract: We have demonstrated self-aligned top-gate amorphous oxide TFTs for large size and high resolution displays. The processes such as source/drain and channel engineering have been developed to realize the self-aligned top gate structure. Ar plasma is exposed on the source/drain region of active layer to minimize the source/drain series resistances. To prevent the conductive channel, N 2 O plasma is also treated on the channel region of active layer. We obtain a field effect mobility of 5.5 cm2/V·s, a threshold voltage of 1.1 V, and a sub-threshold swing of 0.35 V/decade at sub-micron a-GIZO TFTs with the length of 0.67#x00B5;m. Furthermore, a-IZO TFTs fabricated for gate and data driver circuits on glass substrate exhibit excellent electrical properties such as a field effect mobility of 115 cm2/V·s, a threshold voltage of 0.2 V, a sub-threshold swing of 0.2 V/decade, and low threshold voltage shift less than 1 V under bias temperature stress for 3 hr.

957 citations

Journal ArticleDOI
TL;DR: In this paper, the fabrication process and the characteristics of bottom-gate Ga2O3-In2O-3-ZnO (GIZO) thin-film transistors are reported in detail.
Abstract: The fabrication process and the characteristics of bottom-gate Ga2O3-In2O3-ZnO (GIZO) thin-film transistors (TFTs) are reported in detail. Experimental results show that oxygen supply during the deposition of GIZO active layer and silicon oxide passivation layer controls the threshold voltage of the TFT. The field-effect mobility and the threshold voltage of the GIZO TFT fabricated under the optimum process conditions are 2.6 cm2/V ldr s and 3.8 V, respectively. A 4-in QVGA active-matrix organic light-emitting diode display driven by the GIZO TFTs without any compensation circuit in the pixel is successfully demonstrated.

267 citations

Journal ArticleDOI
TL;DR: In this paper, the authors have fabricated high performance and high-stability sol-gel-processed MgInZnO thin films transistors with varying Mg content.
Abstract: We have fabricated high-performance and high-stability sol-gel-processed MgInZnO thin films transistors with varying Mg content. As the Mg content was increased, the turn-on-voltage increased and the off-current decreased. This is because the incorporation of Mg (with low standard electrode potential and high optical band gap, Eopt, when oxidized) causes reduction in the oxygen vacancy, acting as a carrier source, and an increase in Eopt of the film. This results in reduction in carrier concentration of the film. Small grains and smooth morphology by varying the Mg content lead to an improvement of the mobility, on-current, and subthreshold gate swing.

141 citations

Journal ArticleDOI
TL;DR: In this article, the effects of adding Hf into a InZnO (IZO) system, particularly the electrical characteristics of their thin film and thin film transistors (TFTs), were investigated as a function of atomic concentration from 0 to 10 at.
Abstract: The effects of adding Hf into a InZnO (IZO) system, particularly the electrical characteristics of their thin film and thin film transistors (TFTs), were investigated as a function of atomic concentration from 0 to 10 at. % of Hf and Ga/Zn. Because Hf has a high affinity for oxygen in IZO system, the Hf suppresses carrier generation more effectively than does Ga. At 10 at. % of Hf/Zn atomic concentration, the HfInZnO TFTs showed wider on-to-off ratios than those of GaInZnO TFTs due to the low standard-electrode-potential of Hf and sharp subthreshold swings due to low trap density.

124 citations


Cited by
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Journal ArticleDOI
TL;DR: The recent progress in n- and p-type oxide based thin-film transistors (TFT) is reviewed, with special emphasis on solution-processed andp-type, and the major milestones already achieved with this emerging and very promising technology are summarizeed.
Abstract: Transparent electronics is today one of the most advanced topics for a wide range of device applications. The key components are wide bandgap semiconductors, where oxides of different origins play an important role, not only as passive component but also as active component, similar to what is observed in conventional semiconductors like silicon. Transparent electronics has gained special attention during the last few years and is today established as one of the most promising technologies for leading the next generation of flat panel display due to its excellent electronic performance. In this paper the recent progress in n- and p-type oxide based thin-film transistors (TFT) is reviewed, with special emphasis on solution-processed and p-type, and the major milestones already achieved with this emerging and very promising technology are summarizeed. After a short introduction where the main advantages of these semiconductors are presented, as well as the industry expectations, the beautiful history of TFTs is revisited, including the main landmarks in the last 80 years, finishing by referring to some papers that have played an important role in shaping transparent electronics. Then, an overview is presented of state of the art n-type TFTs processed by physical vapour deposition methods, and finally one of the most exciting, promising, and low cost but powerful technologies is discussed: solution-processed oxide TFTs. Moreover, a more detailed focus analysis will be given concerning p-type oxide TFTs, mainly centred on two of the most promising semiconductor candidates: copper oxide and tin oxide. The most recent data related to the production of complementary metal oxide semiconductor (CMOS) devices based on n- and p-type oxide TFT is also be presented. The last topic of this review is devoted to some emerging applications, finalizing with the main conclusions. Related work that originated at CENIMAT|I3N during the last six years is included in more detail, which has led to the fabrication of high performance n- and p-type oxide transistors as well as the fabrication of CMOS devices with and on paper.

2,440 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
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

Journal ArticleDOI
01 Jun 2009
TL;DR: In this paper, a 4.0 inch QVGA AMOLED display using amorphous In-Ga-Zn-Oxide TFTs, focusing on a passivation layer, was developed.
Abstract: We have developed a 4.0 inch QVGA AMOLED display using amorphous In-Ga-Zn-Oxide TFTs, focusing on a passivation layer. Threshold voltage of the TFTs can be controlled to have “normally off” characteristics by using SiOx with a low hydrogen content. Besides, small subthreshold swing and high saturation mobility are obtained.

949 citations

Journal ArticleDOI
TL;DR: A review of the recent progress and major trends in the field of thin-film transistor (TFT) research involving the use of amorphous oxide semiconductors (AOS) is provided in this paper.

836 citations