• 한국진공학회지
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• 제10권3호
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• pp.335-340
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• 2001

RF마그네트론 스퍼터링법으로 사파이어 기판 위에 Ga을 1 wt% 첨가한 ZnO 박막(GZO)을 기판온도 $550^{\circ}C$에서 성장시켜 다결정 박막을 제조하였다. 이러한 박막은 불충분한 전기적 특성이나 PL(Photoluminescence) 특성을 보이고 있다. 이러한 전하농도, 이동도 그리고 PL특성 등과 같은 전기적 광학적 특성을 향상시키고자 질소분위기하에서 RTA(Rapid Thermal Annealing) 법으로 $800^{\circ}C$와 $900^{\circ}C$에서 각각 3분씩 후열처리 하였다. RTA법으로 후열처리한 GZO박막의 비저항은 $2.6\times10^{-4}\Omega$/cm 였으며 전자농도와 이동도는 각각 $3.9\times10^{20}/\textrm{cm}^3$과 60 $\textrm{cm}^2$/V.s 였다. 이러한 물리적 성질들의 향상은 열처리시 원자 크기가 비슷한 도핑된 Ga 원자들이 일부 휘발되는 Zn 빈자리로 치환하면서 침입자리 보다는 치환자리로의 전이에 기인한 것으로 생각된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.354-354
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• 2012

In this study, we report the vertically aligned ZnO nanowires by using different type of Ga-doped ZnO (GZO) thin films as seed layers to investigate how the underlying GZO film micro structure affects the distribution of ZnO nanowires. Arrays of highly ordered ZnO nanowires have been synthesized on GZO thin film seed layer prepared on p-Si substrates ($7-13{\Omega}cm$) with utilize of a pulsed laser deposition (PLD). With the vapor-liquid-solid (VLS) growth process, the ZnO nanowire synthesis carries out no metal catalyst and is cost-effective; furthermore, The GZO seed layer facilitates the uniform growth of well-aligned ZnO nanowires. The influence of the growth temperature and various thickness of GZO seed layer have been analyzed. Crystallinity of grown seed layer was studied by X-Ray diffraction (XRD); diameter and morphology of ZnO nanowires on seed layer were investigated by field emission scanning electron microscopy (FE-SEM). Our results suggest that the GZO seed layer with high c-axis orientation, good crystallinity, and less lattice mismatch is key parameters to optimize the growth of well-aligned ZnO nanowire arrays.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.138-138
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• 2009

Al, Ga and In doped ZnO thin film were prepared by faing targets sputtering as a function of oxygen gas contents at R.T. Base pressure was $2{\times}10^{-6}torr$, and working pressure was 1mTorr. The properties of thin films on the electrical and optical properties of the deposited films were investigated by using a four-point probe (Chang-min), a Hall Effect measurement (Ecopia) and an UV/VIS spectrometer (HP). The minimum resistivities of AZO, GZO and IZO thin film were $6.5{times}10^{-4}[{\Omega}-cm],5.5{\times}10^{-4}[{\Omega}-cm]$ and $4.29{\times}10^{-4}[{\Omega}-cm]$. The average transmittance of over 80% was seen in the visible range.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.261-262
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• 2007

In this study we present the effect of annealing temperatures on the structural, electrical and optical characteristics of Ga-doped ZnO(GZO) films. GZO target have been deposited on corning 7059 glass substrates by DC sputtering. GZO films were annealed at temperatures of 400, 500, $600^{\circ}C$ in air ambient for 20 min. Experimental resulted in as-grown film shows the resistivity of $6{\times}10^{-1}\;{\Omega}{\cdot}cm$ and transmittance under 85%, whereas the electrical and optical properties of film annealed at $500^{\circ}C$ are enhanced up to $1.9{\times}10^{-3}\;{\Omega}{\cdot}cm$ and 90%, respectively.

• 한국전기전자재료학회논문지
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• 제33권6호
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• pp.450-453
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• 2020

In this study, ZnO:Ga thin films were fabricated on a glass substrate using various Ar flows by an RF magnetron sputter system at room temperature. The dependencies of Ar flow on different properties were investigated. An appropriate control over the Ar flow led to the formation of a high-quality thin film. The ZnO:Ga films were formed as a hexagonal wurtzite structure with high (002) preferential orientation. The films exhibited a typical columnar microstructure and a smooth top face. The average transmittance was 85~89% within the visible area. By decreasing the Ar flow, the sheet resistance was decreased due to an increase in the grain size and a decrease in the root mean square roughness. The lowest sheet resistance of 86 Ω/□ was obtained at room temperature for the 40 sccm Ar flow.

• 한국전기전자재료학회논문지
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• 제21권6호
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• pp.499-502
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• 2008

In this work, Ga-doped ZnO (GZO) thin films for gas sensor application were deposited on low temperature co-fired ceramics (LTCC) substrates, by RF magnetron sputtering method. The LTCC substrate is one of promising materials for this application since it has many advantages (e.g., low cost production, high manufacturing yields and easy realizing 3D structure etc.). The LTCC substrates with thickness of $400\;{\mu}m$ were fabricated by laminating 12 green tapes which consist of alumina and glass particle in an organic binder. The structural properties of the fabricated GZO thin film with thickness of 50 nm is analyzed by X-ray diffraction method (XRD) and field emission scanning electron microscope (FESEM). The film shows good adhesion to the substrate. The GZO gas sensors are tested by gas measurement system and show fast response and recovery characteristics to $NO_x$ gas that is 27.2 and 27.9 sec, recpectively.

• 한국전기전자재료학회논문지
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• 제20권12호
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• pp.1044-1048
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• 2007

With development of electronic products the demands for miniaturization and weight-lightening have increased until a recent date. Accordingly, The effort to substitute glass substrates was widely made. However, polymer substrates have weak point that substrates were damaged at high temperature. In this paper, we deposited transparent conductive film at low temperature. And we inserted Au thin film between oxide to compensate for deteriorated electrical characteristics. Ga-doped ZnO(GZO) multilayer coatings were deposited on glass substrate by DC sputtering. The optimization of deposition conditions of both AZO and Au layers were performed to obtain better electrical and optical characteristics in advance. We presumed that the properties of multilayer were affected by the deposition process of both GZO and Au layers. The best multilayer coating exhibited the resistivity of $2.72{\times}10^{-3}\;{\Omega}-cm$ and transmittance of 77 %. From these results, we can confirm a possibility of the application as transparent conductive electrodes.

• 한국표면공학회지
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• 제41권4호
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• pp.142-146
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• 2008

Trivalent ions(Ga, Al, In) doped ZnO films were deposited by DC magnetron sputtering on non-alkali glass substrate at substrate temperature of $300^{\circ}C$. We used the different three types of high density($95%{\sim}$) ceramic sintered disks(doped with $Ga_2O_3$; 6.65 wt%, $Al_2O_3$; 3.0 wt%, $In_2O_3$; 9.54 wt%). This study examined the effect of different dopants(Ga, Al, In) on the electrical, structural, and optical properties of the films. The lowest resistivity of $5.14{\times}10^{-4}{\Omega}cm$ and the highest optical band gap of 3.74 eV were obtained by Ga doped ZnO(GZO) film. All the films had a preferred orientation along the(002) direction, indicating that the growth orientation has a c-axis perpendicular to the substrate surface. The average transmittance of the films was more than 85% in the visible range.

• 한국전기전자재료학회논문지
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• 제25권2호
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• pp.114-120
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• 2012

In this research, we prepared Ga doped zinc oxide(ZnO:Ga, GZO) targets each difference sintering temperature $700^{\circ}C$, $800^{\circ}C$, and doping rate 1 wt.%, 2 wt.%, 3 wt.%. The characteristics of thin film on glass substrates which deposited by facing target sputtering in pure Ar atmosphere are reported. Ga doped zinc oxide film is attracted material through low resistivity, high transmittance, etc. When prepared target powder's structure was investigated by scanning electron microscope, densification and coarsening by driving force was observed. For each ZnO:Ga films with a $Ga_2O_3$ content of 3 wt.% at input power of 45W, the lowest resistivity of $9.967{\times}10^{-4}{\Omega}{\cdot}cm$ ($700^{\circ}C$) and $9.846{\times}10^{-4}{\Omega}{\cdot}cm$ ($800^{\circ}C$) was obtained. the carrier concentration and mobility were $4.09{\times}10^{20}cm^{-3}$($700^{\circ}C$), $4.12{\times}10^{20}cm^{-3}$($800^{\circ}C$) and $15.31cm^2/V{\cdot}s(700^{\circ}C)$, $12.51cm^2/V{\cdot}s(800^{\circ}C)$, respectively. And except 1 wt.% Ga doped ZnO thin film, average transmittance of these samples in the range 350-800 nm was over 80%.

• 한국전기전자재료학회논문지
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• 제22권7호
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• pp.567-571
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• 2009

Polycrystalline ZnO and Ga doped ZnO (GZO) films are deposited on glass substrate by RF magnetron sputtering at room temperature. The characteristics of ZnO and GZO films are investigated with X-ray diffraction measurement, UV-VIS-NIR spectrophotometer $(250{\sim}1200nm)$ and hall measurement. The post-growth thermal treatment of these films is carried out in N2 ambient at $500^{\circ}C$ for 30 min and an hour. ZnO and GZO films have different changing behavior of structural and optical properties by annealing. To use transparent conductive films for solar cell, films should have not only high transmittance but also good electrical property. Although as deposited GZO films have electrical properties than ZnO films, GZO films have not good transmittance properties. Consequently, we succeed that the high transmittance of GZO films is improved by annealing process.