• 반도체디스플레이기술학회지
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• 제9권3호
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• pp.41-45
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• 2010

The ZnO thin films doped with Ga(GZO) and both Ga and Ge(GZO:Ge) were deposited on glass substrate by using RF sputtering system respectively. Structural, morphological and optical properties of the films deposited in the same condition were investigated. Structural properties of the films were investigated by Field Emission Scanning Electron Microscopy, FE-SEM images and X-ray diffraction, XRD analysis. These studies showed shape of films' surface and direction of film growth respectively. It's showed that all films were deposited by vertical orientation strongly. It can be confirmed that all dopants of targets were included in deposited films by results of EDX analysis. UV-Vis spectrometer results showed that all samples had highly transparent characteristics in visible region and have similar 3.28~3.31 eV band gap. It was found that existence of all dopants by EDX analysis. Morphology and roughness of surface of each film were clearly shown by Atomic Force Microscopy, AFM images. It was found in this research that film doped with Ge more dense and stable with hardly any difference in gap energy compared to ZnO films.

• 한국결정성장학회지
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• 제31권2호
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• pp.73-77
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• 2021

RF 마그네트론 스퍼터링 공정에 의해 Ga-doped ZnO 박막이 O2 및 Ar 분위기 하에서 증착 조건에 따라 합성되었으며, N2 분위기에서, 600℃에서 급속열처리(RTA)를 실시하였다. 증착된 ZnO : Ga 박막에 대해 두께를 측정하였고, XRD 패턴 분석에 의해 결정상을 조사하였으며, FE-SEM, AFM 이미지에 의해 박막의 미세구조를 관찰하였다. O2 및 Ar 분위기 기체 종류별로 형성된 박막들의 증착 조건에 따라 X-선 회절 패턴의 (002)면의 세기는 상당한 차이를 나타냈다. O2 조건에서는 Ga doping이 이루어진 단일 박막의 경우에서는 강한 세기의 회절피크가 관찰되었다. O2 및 Ar 조건에서는 Ga doping이 이루어진 다층박막의 경우에서는 다소 약한 세기의 (002) 면의 피크만을 나타내었다. FE-SEM image에서는 박막의 표면입자의 크기는 두께가 증가함에 따라 입자크기가 다소 증가하는 것으로 관찰되었다. O2 및 Ar 분위기 조건 하에서, Ga doping이 이루어진 다층박막의 경우에서는, 비저항은 6.4 × 10-4Ω·cm을 나타냈고, O2 분위기 조건하에서, Ga doping이 이루어진 단일 박막의 경우에서는 저항값이 감소하였고, Ga-doped ZnO 박막의 두께가 2 ㎛로 증가하면서 저항이 감소하였으며, 1.0 × 10-3 Ω·cm의 비교적 낮은 비저항 값을 나타내었다.

• 반도체디스플레이기술학회지
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• 제15권2호
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• pp.11-15
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• 2016

This paper, Ga-doped ZnO (GZO) thin films which were deposited on Corning glass substrate using an magnetron sputtering deposition technology and then the post deposition annealing process was conducted for 30 minutes at different temperature of 100, 200, 300, and $400^{\circ}C$, respectively. So as to investigate the properties for the relevant the Concentration and Oxygen Vacancy with Annealing temperature of Ga-doped ZnO thin films by RF Sputtering method. The Carrier concentration is enhanced as annealing temperature decreases, and also the oxygen vacancy concentration is enhanced as annealing temperature decreased. Oxygen vacancy will decrease along with Carrier concentration. This change in Carrier concentration is related to changes in oxygen vacancy concentration. The figure of merit obtained in this study means that Ga-doped ZnO films which annealed at $400^{\circ}C$ have the lowest Carrier concentration and Oxygen vacancy, which have the highest optoelectrical performance that it could be used as a transparent electrode.

• 한국전기전자재료학회논문지
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• 제25권12호
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• pp.984-989
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• 2012

We have investigated the structural, electrical and optical properties of Ga-doped ZnO (GZO) thin films prepared by RF magnetron sputtering with laboratory-made ZnO targets containing 1, 3, 5, 7 wt% of $Ga_2O_3$ powder as a doping source. The GZO thin films show the typical crystallographic orientation with c-axis regardless of $Ga_2O_3$ content in the targets. The $3,000{\AA}$ thick GZO thin films with the lowest resistivity of $7{\times}10^{-4}{\Omega}{\cdot}cm$ are obtained by using the GZO ($Ga_2O_3$= 5 wt%) target. Optical transmittance of all films shows higher than 80% at the visible region. The optical energy band gap for GZO films increases as the carrier concentration ($n_e$) in the film increases.

• Advances in nano research
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• 제5권3호
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• pp.193-201
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• 2017

ZnO, ZnO: Cu, Ga, and ZnO: Cu, Ga, Ag thin films were obtained by oxidization of ZnS and ZnS: Cu, Ga films deposited onto glass substrates by electron-beam evaporation from ZnS and ZnS: Cu, Ga targets and from ZnS: Cu, Ga film additionally doped with Ag by the closed space sublimation technique at atmospheric pressure. The film thickness was about $1{\mu}m$. The oxidation was carried out at $600-650^{\circ}C$ in air or in an atmosphere containing water vapor. Structural characteristics were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Photoluminescence (PL) spectra of the films were measured at 30-300 K using the excitation wavelengths of 337, 405 and 457.9 nm. As-deposited ZnS and ZnS: Cu, Ga films had cubic structure. The oxidation of the doped films in air or in water vapors led to complete ZnO phase transition. XRD and AFM studies showed that the grain sizes of oxidized films at wet annealing were larger than of the films after dry annealing. As-deposited doped and undoped ZnS thin films did not emit PL. Shape and intensity of the PL emission depended on doping and oxidation conditions. Emission intensity of the films annealed in water vapors was higher than of the films annealed in the air. PL of ZnO: Cu, Ga films excited by 337 nm wavelength exhibits UV (380 nm) and green emission (500 nm). PL spectra at 300 and 30 K excited by 457.9 and 405 nm wavelengths consisted of two bands - the green band at 500 nm and the red band at 650 nm. Location and intensities ratio depended on the preparation conditions.

• 한국전기전자재료학회논문지
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• 제21권3호
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• pp.242-248
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• 2008

The structural, optical and electrical properties of ZnO films doped with 1.5 at% of 3A materials(B, Al, Ga, In) were studied by sol-gel process. The films were found to be c-axis (002) oriented hexagonal structure on glass substrate, when post heated at 500 $^{\circ}C$. The surface of the films showed a uniform and nano size microstructure and the crystalline size of doped films decreased. The lattice constants of ZnO:B/Al/Ga increased than that of ZnO, while ZnO:In decreased. All the films were highly transparent(above 90 %) in the visible region. The energy gaps of ZnO:B/Al/Ga were increased a little, but that of ZnO:In was not changed. The resistivities of ZnO:Al/Ga/In were less than 0.1 $\Omega$cm. All the films showed a semiconductor properties in the light or temperature, however ZnO:In was less sensitive to it. A figure of merit of ZnO:In had the highest value of 0.025 $\Omega^{-1}$ in all samples.

• 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.

• 한국세라믹학회지
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• 제35권6호
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• pp.619-625
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• 1998

Mn doped {{{{ {Zn {Ga }_{2 }O }_{4 } }} thin film phosphors were prepared on Si(100) wafers and ITO coated glass substrates by rf magnetron sputtering technique and the effects of the substrates dopant and the sputtering paramet-ers were analyzed, Changes of the oreintation were observed after annealine tratment. The grain size of {{{{ {Zn {Ga }_{2 }O }_{4 } }} : Mn thin film deposited on Si wafer was smaller than that on ITO/glass substrate which resulted in higher PL intensity. The PL spectra of Mn doped {{{{ {Zn {Ga }_{2 }O }_{4 } }} thin films showed sharp green luminescence spec-trum. According to CL spectrum it could be concluded that Mn ions acted as an actuator for green emission by substituting Zn atom sites.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.296-296
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• 2010

In this work, we report the effect of substrate on the growth of Ga-doped ZnO (GZO) thin films. GZO thin films were deposited on various substrates by using pulsed laser deposition (PLD). The structural properties, surface morphologies, and electrical properties were investigated. From the results of HRXRD, c-plane (0002) oriented growth of GZO films was confirmed on $Al_2O_3$ (0001). On the other hand, the GZO films on LAO (100) substrates were grown along the a-axis. The obvious differences on the electrical properties of each film were also obtained.

• 전기학회논문지
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• 제59권1호
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• pp.108-112
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• 2010

Design of experiment (DOE) method is employed for a systematic and highly efficient optimization of Ga-doped ZnO thin films synthesized by pulsed laser deposition (PLD) process. We sequentially adopted fractional-factorial design (FD) and central composite design (CCD) of the DOE methods. In fractional-FD stage, significant factors to make conductive electrode are found to target-substrate (T-S) distance and oxygen partial pressure. Moreover, correlation among the process factors is elucidated using surface profile modeling. Electrical properties of the GZO films grown on a glass substrate had been optimized to find that the lowest electrical resistivity of about $1.8'10^{-4}Wcm$ which was acquired with the T-S distance and the oxygen pressure of 4 cm and 7 mTorr, respectively. During the DOE-fueled optimization process, the transparency of the GZO films is ensured higher than 85 %.