• Journal of Information Display
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• 제10권4호
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• pp.137-142
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• 2009

Transparent top-gate Al-Zn-Sn-O (AZTO) thin-film transistors (TFTs) with an $Al_2O_3$ protective layer (PL) on an active layer were studied, and a transparent 2.5-inch QCIF+AMOLED (active-matrix organic light-emitting diode) display panel was fabricated using an AZTO TFT backplane. The AZTO active layers were deposited via RF magnetron sputtering at room temperature, and the PL was deposited via two different atomic-layer deposition (ALD) processes. The mobility and subthreshold slope were superior in the TFTs annealed in vacuum and with oxygen plasma PLs compared to the TFTs annealed in $O_2$ and with water vapor PLs, but the bias stability of the TFTs annealed in $O_2$ and with water vapor PLs was excellent.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.207.2-207.2
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• 2013

Oxide-based thin film transistors have been attempted as powerful candidates for driving circuits for active-matrix organic light-emitting diodes and transparent electronics. The oxide TFTs are based on the amorphous multi-component oxides involving zinc, indium, and/or tin elements as main cation sources. The current work employed RF sputtering in order to deposit zinc-tin oxide thin films applicable to transparent oxide thin film transistors. The deposited thin film was characterized and probed in terms of materials and devices. The physical/chemical characterizations were performed using X-ray diffraction, Atomic Force Microscopy, Spectroscopic Ellipsometry, and X-ray Photoelectron Spectroscopy. The thin film transistors were fabricated using a bottom-gated structure where thermally-grown silicon oxide layers were applied as gate-dielectric materials. The inherent properties of oxide thin films are combined with the corresponding device performances with the aim to fabricating the multi-component oxide thin films being optimized towards transparent electronics.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.110.2-110.2
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• 2012

We reported on antireflective ZnSnO (ZTO)/Ag bilayer and ZTO/Ag/ZTO trilayer source/drain (S/D) electrodes for all-transparent ZTO channel based thin film transistors (TFTs). The ZTO/Ag bilayer is more transparent (83.71%) and effective source/drain (S/D) electrodes for the ZTO channel/Al2O3 gate dielectric/ITO gate electrode/glass structure than ZTO/Ag/ZTO trilayer because the bottom ZTO layer in the trilayer increasea contact resistance between S/D electrodes and ZTO channel layer and reduce the antireflection effect. The ZTO based all-transparent TFTs with ZTO/Ag bilayer S/D electrode showed a saturation mobility of 4.54cm2/Vs and switching property (1.31V/decade) comparable to TTFT with Ag S/D electrodes.

• 한국전기전자재료학회논문지
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• 제26권4호
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• pp.289-293
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• 2013

We have studied structural, optical, and electrical properties of the Ga-doped ZnO (GZO) thin films being usable in transparent conducting oxides. The GZO thin films were deposited on the corning 1737 glass plate by the RF magnetron sputtering system. To find optimal properties of GZO for transparent conducting oxides, the Ar gas in sputtering process was varied as 40, 60, 80 and 100 sccm, respectively. As reaction gas decreased, the crystallinity of GZO thin film was increased, the optical bandgap of GZO thin film increased. The transmittance of the film was over 80% in the visible light range regardless of the changes in reaction gas. The measurement of Hall effect characterizes the whole thin film as n-type, and the electrical property was improved with decreasing reaction gas. The structural, optical, and electrical properties of the GZO thin films were affected by Ga dopant content in GZO thin film.

• 한국전기전자재료학회논문지
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• 제24권3호
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• pp.177-181
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• 2011

We have studied structural, optical, and electrical properties of the Al-doped ZnO (AZO) thin films being usable in transparent conducting oxides. The AZO thin films were deposited on the corning 1737 glass plate by the RF magnetron sputtering system. To find optimal properties of AZO for transparent conducting oxides, the RF power in sputtering process was varied as 40 W, 60 W, and 80 W, respectively. As RF power increased, the crystallinity of AZO thin film was decreased, the optical bandgap of AZO thin film increased. The transmittance of the film was over 80% in the visible light range regardless of the changes in RF power. The measurement of Hall effect characterizes the whole thin film as n-type, and the electrical property was improved with increasing RF power. The structural, optical, and electrical properties of the AZO thin films were affected by Al dopant content in AZO thin film.

• Journal of Information Display
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• 제9권3호
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• pp.8-11
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• 2008

A novel non-alkoxide sol-gel process for synthesizing Ga-doped ZnO thin film on glass was derived for possible use as a transparent electrode in flat-panel displays, using zinc acetate dehydrate as the starting material. The structural and electrical properties of thin films have been characterized as functions of Ga addition and post-heat-treatments. Their carrier density, Hall mobility, and optical transmittance were measured and discussed herein to explain the characteristics of the sol-gel-derived Ga-doped ZnO thin film on glass.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권1호
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• pp.26-29
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• 2006

Transparent ZnO thin films were prepared by KrF pulsed laser deposition (PLD) technique and applied to a bottom-gate type thin film transistor device as an active channel layer. A high conductive crystalline Si substrate was used as an metal-like bottom gate and SiN insulating layer was then deposited by LPCVD(low pressure chemical vapour deposition). An aluminum layer was then vacuum evaporated and patterned to form a source/drain metal contact. Oxygen partial pressure and substrate temperature were varied during the ZnO PLD deposition process and their influence on the thin film properties were investigated by X-ray diffraction(XRD) and Hall-van der Pauw method. Optical transparency of the ZnO thin film was analyzed by UV-visible phometer. The resulting ZnO-TFT devices showed an on-off ration of $10^6$ and field effect mobility of 2.4-6.1 $cm^2/V{\cdot}s$.

• 반도체디스플레이기술학회지
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• 제13권1호
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• pp.91-95
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• 2014

(F,Ga) co-doped ZnO thin film on glass substrate was fabricated via a simple non-alkoxide sol-gel spin-coating. Contrary to the F single doped ZnO thin film, the (F,Ga) co-doped thin film showed a significant reduce in electrical resistivity after a second post-heat-treatment in reducing environment. The resulting decrease in electrical resistivity with Ga co-doping is considered to be resulted from the increases both carrier density and mobility. The optical transmittance of the (F,Ga) co-doped thin film in the visible range showed higher transmittance with Ga co-doping compared with F single doped ZnO thin film.

• 대한금속재료학회지
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• 제49권2호
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• pp.192-196
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• 2011

The multi-layered thin film with an ITO/Ag/ITO structure was produced on PET by using magnetron reactive sputtering method. First, 30 nm of ITO thin film was coated on PET by using normal temperature process. Then 20-52 nm of the Ag thin film was coated. Lastly, 30 nm of ITO thin film was coated on Ag layer. The sample of the 20 nm Ag thin film showed more than 70% transmission and a $2.7{\Omega}/{\Box}$ sheet resistance. When compared to the existing single-layered transparent conducting thin film, multi-layered film was found to be superior with about $5{\Omega}/{\Box}$ less sheet resistance. However, since the Ag layer became thinner, the band gap energy needs to be increased to more than 3.5 eV.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.860-863
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• 2007

ZnO nano film for transparent thin film transistors is prepared by injection type source delivery system of atomic layer deposition. By using this delivery system the source delivery pulse time can dramatically be reduced to 0.005s in ALD system. ZnO nanofilms obtained at $150^{\circ}C$ are characterized.