• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.73-73
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• 2008

LCD, OLED 등의 평판디스플레이와 RFID tag, smart card 등의 구동 소자 등 넓은 산업 분야에 적용하기 위하여 PVP 유기물과 병합된 ZnO 산화물을 이용하여 차세대 박막트랜지스터의 제작 공정과 전기적 특성을 조사하였다. 또한 제작된 박막트랜지스터의 전기적 특성을 향상시키기 위하여 유, 무기 박막의 특성을 분석하고, $O_2$ plasma 처리를 통하여 유-무기 박막간 계면 접합력 및 계면 효과의 변화특성이 OITFT 특성에 미치는 영향을 조사하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1034-1037
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• 2004

In this paper we fabricated a test panel for AMOLED on glass and PET substrate. The test panel consisted of the various size of OTFTs and OLEDs and the current driving capability of OTFTs for OLEDs has been investigated. OTFTs were made of the inverted staggered structure and employed polyvinylphenol (PVP) as the gate insulator and pentacene thin film as the active layer. The OTFTs produced the filed effect mobility of 0.3$cm^2$/V.sec and on/off current ratio of $10^5$. OLEDs consisted of TPD for HTL and Alq3 for EML with 35nm thick, generating green monochrome light. We found that OTFT with channel length of 70${\mu}m$and channel width of over 3.5mm provided the sufficient current to OLED to generate the luminescence of 0.3Cd/$m^2$.

• Journal of the Korean Vacuum Society
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• v.22 no.3
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• pp.131-137
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• 2013

The thin insulator films for organic memory device were made by the plasma polymerization method using the styrene monomer which was not the wet process but the dry process. For the formation of stable plasma, we make an effort for controlling the monomer with bubbler and circulator system. The thickness of plasma polymerized styrene insulator layer was 430 nm, the thickness of the Au memory layer was 7 nm thickness of plasma polymerized styrene tunneling layer was 30, 60 nm, the thickness of pentacene active layer was 40 nm, the thickness of source and drain electrodes were 50 nm. The I-V characteristics of fabricated memory device got the hysteresis voltage of 45 V at 40/-40 V double sweep measuring conditions. If it compared with the results of previous paper which was the organic memory with the plasma polymerized MMA insulation thin film, this result was greater than 18 V, the improving ratio is 60%. From the paper, styrene indicated a good charge trapping characteristics better than MMA. In the future, we expect to make the organic memory device with plasma polymerized styrene as the memory thin film.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.4
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• pp.286-290
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• 2020

The formation of inorganic thin films in low-temperature solution processes is necessary for a wide range of commercial applications of organic electronic devices. Aluminum oxide thin films can be utilized as barrier films that prevent the deterioration of an electronic device due to moisture and oxygen in the air. In addition, they can be used as the gate insulating layers of a thin film transistor. In this study, aluminum oxide thin film were formed using two methods simultaneously, a thermal process and the DUV process, and the properties of the thin films were compared. The result of converting aluminum nitrate hydrate to aluminum oxide through a hybrid process using a thermal treatment and DUV was confirmed by XPS measurements. A film-based a-IGZO TFT was fabricated using the formed inorganic thin film as a gate insulating film to confirm its properties.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.133-135
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• 2007

PMMA (polymethyl metha crylate) 유기막의 농도별 최적화를 위하여 1, 2, 4, 6, 8 wt.%의 PMMA 농도별로 Al/PMMA/ITO/Glass 구조의 MIM (metal- insulator-metal) 캐패시터 소자를 제작하였다. 유기 절연층의 형성은 ITO/Glass 기판 위에 PMMA를 용질로, Anisle을 용매로 사용하여 스핀코팅법으로 소자를 형성하였다. 제작된 소자에 대해 농도에 따른 전기적 특성을 조사한 결과 누설전류는 2wt.% 농도의 PMMA로 제작된 소자에서 0.3 pA로 가장 우수한 결과를 얻을 수 있었다. 또한 동일한 PMMA 농도로 제작된 캐패시터 소자의 정전용량은 1.2 nF으로 가장 좋은 결과를 얻을 수 있었으며, 계산된 값과 매우 유사한 값을 얻을 수 있었다.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.1 s.38
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• pp.37-42
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• 2006

The preparation and processing of PVP-gate insulators on the device performance have been studied in the fabrication of organic thin film transistors (OTFTs). One of polyvinyl series, poly-4-vinyl phenol(PVP) was used as a solute and propyleneglycol monomethyl etheracetate(PGMEA) as a solvent in the formation of organic gate solutions. The cross-linking of organic insulators was also attempted by adding the thermosetting material, poly (melamine-co-formaldehyde) as a hardener in the compounds. From the measurements of electrical insulating characteristics of metal-insulator-metal (MIM) samples, PVP-based insulating layers showed lower leakage current according to the increase of concentration of PVP and poly (melamine-co-formaldehyde) to PGMEA in the formation of organic solutions. The PVP(20 wt%) copolymer with composition of 20 wt% PVP to PGMEA and cross-linked PVPs in which 5 wt% and 10 wt% poly (melamine-co-formaldehyde) hardeners had been additional]y mixed into PVP(20 wt%) copolymers were used as gate dielectrics in the fabrication of OTFTs, respectively. In our experiments, the maximum field effect mobility of $0.31cm^2/Vs$ could be obtained in the 5 wt% cross-linked PVP(20 wt%) device and the highest on/off current ratio of $1.92{\times}10^5$ in the 10 wt% cross-linked PVP(20 wt%) device.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.341.1-341.1
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• 2014

In the advanced material for the next generation display device, transparent amorphous oxide semiconductors (TAOS) are promising materials as a channel layer in thin film transistor (TFT). The TAOS have many advantages for large-area application compared with hydrogenated amorphous silicon TFT (a-Si:H) and organic semiconductor TFT. For the reasonable characteristics of TAOS, The a-IGZO has the excellent performances such as low temperature fabrication (R.T~), high mobility, visible region transparent, and reasonable on-off ratio. In this study, we investigated how the electric characteristics and physical properties are changed as various oxygen ratio when magnetron sputtering. we analysis a-IGZO film by AFM, EDS and I-V measurement. decreasing the oxygen ratio, the threshold voltage is shifted negatively and mobility is increasing. Through this correlation, we confirm the effect of oxygen ratio. We fabricated the bottom-gate a-IGZO TFTs. The gate insulator, SiO2 film was grown on heavily doped silicon wafer by thermal oxidation method. a-IGZO channel layer was deposited by RF magnetron sputtering. and the annealing condition is $350^{\circ}C$. Electrode were patterned Al deposition through a shadow mask(160/1000 um).

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.7
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• pp.1-8
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• 2008

We fabricated flexible electrophoretic display(EPD) driven by organic thin film transistors(OTFTs) on plastic substrate. We designed the W/L of OTFT to be 15, considering EPD's transient characteristics. The OTFTs employed bottom contact structure and used Al for gate electrode, the cross-linked polyvinylphenol for gate insulator, pentacene for active layer. The plastic substrate was coated by PVP barrier layer in order to remove the islands which were formed after pre-shrinkage process and caused the electrical short between bottom scan and top data metal lines. Pentacene active layer was confined within the gate electrodes so that the off current was controlled and reduced by gate electrodes. Especially, PVA/Acryl double layers were inserted between EPD panel and OTFT-backplane in order to protect OTFT-backplane from the damages created by lamination process of EPD panel on the backplane and also accommodate pixel electrodes through via holes. From the OTFT-backplane the mobility was $0.21cm^2/V.s$, Ion/Ioff current ratio $10^5$. The OTFT-EPD panel worked successfully and demonstrated to display some patterns.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.219-226
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• 2013

Organic semiconductor-based soft electronics has potential advantages for next-generation electronics and displays, which request mobile convenience, flexibility, light-weight, large area, etc. Organic field-effect transistors (OFET) are core elements for soft electronic applications, such as e-paper, e-book, smart card, RFID tag, photovoltaics, portable computer, sensor, memory, etc. An optimal multi-layered structure of organic semiconductor, insulator, and electrodes is required to achieve high-performance OFET. Since most organic semiconductors are self-assembled structures with weak van der Waals forces during film formation, their crystalline structures and orientation are significantly affected by environmental conditions, specifically, substrate properties of surface energy and roughness, changing the corresponding OFET. Organo-compatible insulators and surface treatments can induce the crystal structure and orientation of solution- or vacuum-processable organic semiconductors preferential to the charge-carrier transport in OFET.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1700-1701
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• 2011

본 논문에서는 게이트 절연막인 poly(4-vinylphenol) (PVP) 용제 농도 변화에 따른 유기 박막 트랜지스터를 제작하고 그 특성을 분석하였다. PVP는 propylene glycol monomethyl ether acetate(PGMEA) 와 poly melamine-co-formaldehyde (CLA)를 혼합하여 cross linked PVP를 만들어 사용하였다. Cross-liked PVP의 CLA 농도 비율을 각각 6 wt%, 9 wt%로 변화시켜 유기 박막 트랜지스터를 제작하고 소자의 전기적 특성을 분석 하였다.