• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.898-901
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• 2005

We propose a novel pixel structure using bootstrapped voltage programming for amorphoussilicon TFT backplane of AM-OLED (Active Matrix-Organic Light Emitting Diode) displays. The proposed structure is composed of two TFTs and one capacitor. It operates at low drive voltage ($0{\sim}5V$) which can reduce power consumption comparing with the conventional pixel circuit structure using same OLED material. Also, it can easily control dark level and use commercial mobile LCD ICs. In this paper, we describe the operating principle and the characteristics of the proposed pixel structure and verify the performance by SPICE simulation comparing with the conventional pixel structure.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1515-1517
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• 2001

In this work the electrical characteristics of organic TFTs with the semiconductor-insulator interfaces have been interested. Pentacene is used as an active semiconducting layer. The semiconductor layer of pentacene was thermally evaporated in vacuum at a pressure of about $2{\times}10^{-6}$ Torr and at a deposition rate of 0.3$\AA$/sec. Aluminium and gold were used for gate and source/drain electrodes. before pentacene is deposited on the insulator, the gate dielectric surfaces of two samples were rubbed with lateral and perpendicular to direction of the channel length respectively.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1407-1411
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• 2003

Due to the heat confinement in the shallow region of the target for a short time scale, pulsed laser annealing has received increasing interest for the fabrication of poly-Si thin film transistors(TFTs) on glass as a low cost substrate in the flat panel displays. The formation and growth mechanisms of poly silicon(poly-Si) grains in thin films are investigated using an excimer laser crystallization system. To understand the crystallization mechanism, the grain formations are observed by FESEM analysis. The optical reflectance and transmittance during the crystallization process are measured using HeNe laser optics. A two-step ELC(Excimer Laser Crystallization) process is applied to enhance the grain formation uniformity.

• Laser Solutions
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• v.6 no.2
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• pp.9-17
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• 2003

Due to the heat confinement in the shallow region of the target for a short time scale, pulsed laser annealing has received an increasing interest for the fabrication of poly-Si thin film transistors(TFTs) on glass as a low cost substrate in the flat panel displays. The formation and growth mechanisms of poly silicon(poly-Si) grains in thin films are investigated using an excimer laser crystallization system. To understand the crystallization mechanism, the grain formations are observed by FESEM photography. The optical reflectance and transmittance during the crystallization process are measured using HeNe laser optics. A two-step ELC(Excimer Laser Crystallization) process is applied to enhance the grain formation uniformity.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.6
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• pp.331-337
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• 2010

Aluminum nitride (AlN) thin films containing various amounts of Co content have been deposited by using a two-facing targets type sputtering (TFTS) system. The deposited films were also annealed successively and isothermally at different temperatures. Annealing treatment can control the physical properties as well as the microstructure of AlN films with Co particles. High magnetization and high resistivity are obtainable in AlN films containing dispersed Co particles. The coercivity of the films does not depend on annealing time, but it increases with increasing annealing temperature due to the increase of the grain size. A high saturation magnetization of 46 kG and resistivity of 2200 ${\mu}{\Omega}$-cm was obtained for AlN films containing 25 at% Co.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1151-1152
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• 2015

Silicon zinc oxide (SZO) thin films were deposited via co-sputtering. Two kinds of post-treatment, furnace annealing and hot pressing, were carried out on the deposited SZO films. The effects of the post-treatment on the chemical bond and surface roughness of the deposited SZO films were analyzed as functions of the post-treatment conditions that were used. It was observed from the X-ray photoelectron spectroscopy (XPS) results that the amount of Si-O bonds in the SZO film drastically increased after the low-temperature furnace annealing. The experiment results showed that the hot pressing method would be favorable as it could improve the electrical characteristics of the SZO-TFTs.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.770-772
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• 2002

A new dry-processing method of organic gate dielectric film in field-effect transistors (FETs) was proposed. The method use vapor deposition polymerization (VDP) that is continuous and low temperature process. It has the advantages of shadow mask patterning and dry processing in flexible low-cost large area applications. Here, 80 nm-thick Al as a gate electrode was evaporated through shadow mask. Gate insulators used two different polyimides. The one material was 4,4'-oxydiphtahlic anhydride (ODPA) and 4,4'-oxydianiline (ODA). Another was 2,2-bis(3,4-dicarboxyphenyl) Hexafluoropropane Dianhydride (6FDA) and 4,4' -oxydianiline (ODA). These were co-deposited by high-vaccum thermal-evapora and cured at 150 $^{\circ}C$ for 1 hour, respectively. Pentacene as a semiconductor and 100 nm-thick Au as a source and drain electrode were evaporated through shadow mask.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.184-187
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• 2002

In this work, the electrical characteristics of organic thin film transistors with the stacked organic gate insulators have been studied. PVP(Polyvinylphenol) and polystyrene were used as gate insulating materials. Both the high dielectric constant of PVP and better insulating capability of polystyrene were compensatorily adopted in two different stacking orders of PVP-polystyrene and polystyrene-PVP. The output characteristics of the device with the stacked gate insulator showed substantial improvement compared with those of the devices with either PVP or polystyrene gate insulator: Furthermore, these stacked organic gate insulators can differently affect the TFT characteristics with the stacking orders. The electrical properties of TFTs with organic gate insulators stacked in different orders are discussed.

• Journal of Information Display
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• v.10 no.2
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• pp.54-61
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• 2009

The results of the optimization of the organic passivation process for fabricating thin-film transistors (TFTs) with a high aperture ratio on a seventh-generation glass (2200${\times}$1870 mm) substrate for LCD-TV panels are reported herein. The optimization of the organic passivation process has been verified by checking various factors, including the material properties (e.g., thickness, stain, etching, thermal reflow) and the effects on the TFT operation (e.g., gate/data line delay and display-driving properties). The two main factors influencing the organic passivation process are the optimization of the final thickness of the organic passivation layer, and the gate electrode. In conclusion, the minimum possible final thickness was found to be $2.42{\um}m$ via simulation and pilot testing, using the full-factorial design. The optimization of the organic passivation layer was accomplished by improving its brightness by over 10 cd/$m^2$ (ca. 2% luminance) compared to that of the conventional organic passivation process. The results of this research also help reduce the reddish stain on display panels.

• Journal of the Korean Society for Heat Treatment
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• v.24 no.1
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• pp.16-22
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• 2011

Al-Co/AlN-Co multilayer films with different layer thicknesses were prepared by using a two-facing target type D.C sputtering (TFTS) system. The deposited films were annealed isothermally at different temperatures and their microstructure, magnetic properties and resistivity were investigated. The magnetization of as-deposited films is very small irrespective of layer thickness. It was found that annealing conditions and layer thickness ratio (LTR) of Al-Co to AlN-Co can control the microstructure as well as the physical properties of the prepared films. The resistivity and magnetization increase and the coercivity decreases with decreasing LTR. High resistivity and sufficient magnetization were obtained for the films with LTR = 0.35. Films having such considerable magnetization and resistivity will be a potential candidate to be used for a high density recording material.