scispace - formally typeset
Search or ask a question
Author

Dong Myong Kim

Bio: Dong Myong Kim is an academic researcher from Kookmin University. The author has contributed to research in topics: Thin-film transistor & Threshold voltage. The author has an hindex of 25, co-authored 216 publications receiving 3378 citations.


Papers
More filters
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, an extraction technique for subgap density of states (DOS) in an n-channel amorphous InGaZnO thin-film transistor (TFT) by using multifrequency capacitancevoltage (C -V) characteristics is proposed and verified by comparing the measured I-V characteristics with the technology computer-aided design simulation results incorporating the extracted DOS as parameters.
Abstract: An extraction technique for subgap density of states (DOS) in an n-channel amorphous InGaZnO thin-film transistor (TFT) by using multifrequency capacitance-voltage (C -V) characteristics is proposed and verified by comparing the measured I- V characteristics with the technology computer-aided design simulation results incorporating the extracted DOS as parameters. It takes on the superposition of exponential tail states and exponential deep states with characteristic parameters for N TA = 1.1 × 1017 cm-3 · eV-1, N DA = 4 × 1015 cm-3 · eV-1, kT TA = 0.09 eV, and kT DA = 0.4 eV. The proposed technique allows obtaining the frequency-independent C-V curve, which is very useful for oxide semiconductor TFT modeling and characterization, and considers the nonlinear relation between the energy level of DOS and the gate voltage V GS. In addition, it is a simple, fast, and accurate extraction method for DOS in amorphous InGaZnO TFTs without optical illumination, temperature dependence, and numerical iteration.

139 citations

Journal ArticleDOI
TL;DR: In this paper, a photonic high-frequency capacitance-voltage (HF C-V) response of metal-oxide semiconductor (MOS) capacitors is reported for the analysis of interface states in MOS systems.
Abstract: A new characterization method based on the photonic high-frequency capacitance-voltage (HF C-V) response of metal-oxide semiconductor (MOS) capacitors is reported for the analysis of interface states in MOS systems. An optical source with a photon energy less than the silicon band-gap (h/spl nu/ = 0.799 eV < E/sub g/ = 1.11 eV) is employed for the photonic characterization of interface states (Bit) distributed in the photoresponsive energy band (E/sub c/ h/spl nu/ < E/sub it/ < E/sub c/) in NMOS capacitors with a polysilicon gate. Assuming a uniform distribution of the trap levels, the density of interface states (D/sub it/) was observed to be D/sub it/ 1-5 /spl times/ 10/sup 11/ eV/sup -1/ cm/sup -2/ in the photoresponsive energy band.

135 citations

Journal ArticleDOI
TL;DR: A sandwich-like structured strain sensor with excellent optical transparency based on highly purified, solution-processed, 99% metallic CNT-polydimethylsiloxane (PDMS) composite thin films that can be applied and controlled based on the need of individual applications.
Abstract: The demands for transparent, flexible electronic devices are continuously increasing due to their potential applications to the human body. In particular, skin-like, transparent, flexible strain sensors have been developed to realize multifunctional human–machine interfaces. Here, we report a sandwich-like structured strain sensor with excellent optical transparency based on highly purified, solution-processed, 99% metallic CNT–polydimethylsiloxane (PDMS) composite thin films. Our CNT–PDMS composite strain sensors are mechanically compliant, physically robust, and easily fabricated. The fabricated strain sensors exhibit a high optical transparency of over 92% in the visible range with acceptable sensing performances in terms of sensitivity, hysteresis, linearity, and drift. We also found that the sensitivity and linearity of the strain sensors can be controlled by the number of CNT sprays; hence, our sensor can be applied and controlled based on the need of individual applications. Finally, we investigate...

122 citations

Journal ArticleDOI
TL;DR: In this paper, the acceptor-like density of states (DOS) is extracted from the optical response of capacitance-voltage characteristics and confirmed by the TCAD simulation comparing with the measured data.
Abstract: In order to model dc characteristics of n-channel amorphous InGaZnO thin-film transistors from experimentally obtained density of states (DOS), the acceptorlike DOS is extracted from the optical response of capacitance-voltage characteristics and confirmed by the technology computer-aided design (TCAD) simulation comparing with the measured data. Extracted DOS is a linear superposition of two exponential functions (tail and deep states), and its incorporation into TCAD model reproduces well the experimental current-voltage characteristics over the wide range of the gate and drain voltages. The discrepancy at higher gate voltage is expected to be improved by incorporating a gate voltage-dependent mobility in the model.

98 citations


Cited by
More filters
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

Journal ArticleDOI
TL;DR: Most device issues, such as uniformity, long-term stability against bias stress and TFT performance, are solved for a-IGZO TFTs.

1,573 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