• 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.

• 센서학회지
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• 제27권3호
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• pp.182-185
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• 2018

Zinc oxide (ZnO) thin films have the advantages of growing at a low temperature and obtaining high charge mobility (carrier mobility) [1]. Furthermore, the zinc oxide thin film can be used to control application resistance depending on its oxygen content. ZnO has the desired physical properties, a transparent nature, with a flexible display that makes it ideal for use as a thin-film transistor. Though these transparent flexible thin-film transistors can be manufactured in various manners, manufacturing large-area transistors using a solution process is easier owing to the low cost and flexible substrate. The advantage of being able to process at low temperatures has been attracting attention as a preferred method. However, in the case of a thin-film transistor fabricated through a solution process, it is reported that charge mobility is lower. To improve upon this, a method of improving the crystallinity through heat treatment and increasing electron mobility has been reported. However, as the heat treatment temperature is relatively high at $500^{\circ}C$, an application where a flexible substrate is absent would be more suitable.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.609-614
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• 2014

We fabricated amorphous zinc tin oxide (ZTO) transparent thin-film transistors (TTFTs). The effects of Al electrode on the mobility and threshold voltage of the ZTO TTFTs were investigated. It was found that the aluminum (Al)-ZTO contact decreased the mobility and increased the threshold voltage. Traps, originating from $AlO_x$, were assumed to be the cause of degradation. An indium tin oxide film was inserted between Al and ZTO as a buffer layer, forming an ohmic contact, which was revealed to improve the performance of ZTO TTFTs.

• 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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• 제28권7호
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• pp.433-438
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• 2015

Zinc tin oxide transparent thin film transistors (ZTO TTFTs) were fabricated by using $n^+$ Si wafers as gate electrodes. Indium (In), aluminum (Al), indium tin oxide (ITO), silver (Ag), and gold (Au) were employed for source and drain electrodes, and the mobility and the threshold voltage of ZTO TTFTs were observed as a function of electrode. The ZTO TTFTs adopting In as electrodes showed the highest mobility and the lowest threshold voltage. It was shown that Ag and Au are not suitable for the electrodes of ZTO TTFTs. As the results of this study, it is considered that the interface properties of electrode/ZTO are more influential in the properties of ZTO TTFTs than the conductivity of electrode.

• 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.

• 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.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.99-99
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• 2014

Transparent oxide semiconductors (TOSs) are. currently attracting attention for application to transparent electrodes in optoelectronic devices and active channel layers in thin-film transistors. One of the key issues for the realization of next generation transparent electronic devices such as transparent complementary metal-oxide-semiconductor thin-film transistors (CMOS TFTs), transparent wall light, sensors, and transparent solar cell is to develop p-type TOSs. In this talks, I will introduce issues and status related to p-type TOSs such as LnCuOQ (Ln=lanthanide, Q=S, Se), $SrCu_2O_2$, $CuMO_2$ (M=Al, Ga, Cr, In), ZnO, $Cu_2O$ and SnO. The growth and properties of SnO and Cu-based oxides and their application to electronic devices will be discussed.

• 전기전자학회논문지
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• 제23권2호
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• pp.375-379
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• 2019

Zn와 Sn의 원자비가 2:1인 타겟을 고주파 스파터링하여 $ZnO-SnO_2(ZTO)$박막을 증착하고 열처리에 따른 구조적 특성변화를 조사하였다. 이 ZTO박막을 활성층으로 사용하여 투명박막트랜지스터(TTFT)를 제조하였다. 약 100 nm 두께의 $SiO_2$위에 100 nm의 $Si_3N_4$막을 기른 후 TTFT의 게이트 절연막으로 채택하였다. TTFT의 전달 특성을 통해 이동도, 문턱전압, 작동전류-차단전류 비($I_{on}/I_{off}$), 계면트랩밀도를 구하였다. 기판 가열 및 후속 열처리가 ZTO TTFT의 특성 변화에 미치는 영향을 분석하였다.

• 한국전기전자재료학회논문지
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• 제27권7호
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• pp.433-437
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• 2014

Transparent thin film transistors were fabricated on $n^+$-Si wafers coated by $Al_2O_3/SiO_2$. Zinc tin oxide (ZTO) films deposited by rf magnetron sputtering were employed for active layers. The mobility (${\mu}s$), threshold voltage ($V_T$), and subthreshold swing (SS) dependances on ZTO thickness were analyzed. The $V_T$ decreased with increasing ZTO thickness. The ${\mu}s$ raised from $5.1cm^2/Vsec$ to $27.0cm^2/Vsec$ by increasing ZTO thickness from 7 nm to 12 nm, and then decreased with ZTO thickness above 12 nm. The SS was proportional to ZTO thickness.