• 한국표면공학회지
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• 제40권4호
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• pp.165-169
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• 2007

Compared to conventional Indium Tin Oxide (ITO) film deposition methods, cesium (Cs) assisted sputtering offers higher film characteristics in terms of electrical, mechanical and optical properties. However, it showed highly non-linear characteristics between process input factors and equipment responses. Therefore, to maximize film quality, optimization of manufacturing process is essential and process characterization is the first step for process optimization. For this, we designed 2 level design of experiment (DOE) to analyze ITO film characteristics including film thickness, resistivity and transmittance. DC power, pressure, carrier flow, Cs temperature and substrate temperature were selected for process input variables. Through statistical effect analysis methods, relation between three types of ITO film characteristics and five kinds of process inputs are successfully characterized and eventually, it can be used to optimize Cs assisted sputtering processes for various types of film deposition.

• 반도체디스플레이기술학회지
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• 제5권1호
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• pp.13-16
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• 2006

AIN thin films were prepared on amorphous glass and $SiO_2(1{\mu}m)/Si(100)$ substrate by the facing targets sputtering (FTS) apparatus, which can provide high density plasma, a high deposition rate at a low working gas pressure. The AIN thin films were deposited at a different nitrogen gas flow rate ($1.0{\sim}0.3$) and other sputtering parameters were fixed such as sputtering power of 200w, working pressures of 1mTorr and AIN thin film thickness of 800 nm, respectively. The thickness and crystallographic characteristics of AIN thin films as a function of $N_2$ gas flow rate $[N_2/(N_2+Ar)]$ were measured by $\alpha$-step and an X-ray diffraction (XRD) instrument. And the c-axis preferred orientations were evaluated by rocking curve. In the results, we could prepared the AIN thin film with c-axis preferred orientation of about $5^{\circ}$ on substrate temperature R.T. at nitrogen gas flow rate 0.7.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권4호
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• pp.232-238
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• 2000

PZT thin films(3500 ) have been prepared onto $Pt/Ti/SiO_2/Si$ substrates with a RF magnetron sputtering system using PB1.05(Zr0.52,Ti0.48)O3 ceramic target. We used two-step annealing techniques. As the RTA times and temperatures were increased, crystallization of PZT thin films were enhanced. The ferroelectric characteristics of PZT capacitors fabricated at $700^{\circ}C$ for 60 seconds were like these remanent polarization were $12.1 \muC/cm^2$, coercive field were 110 kV/cm, leakage current density were $4.1\times10-7 A/cm^2,\; \varepsilonr=442,$ and remanent polarization were decreased by 22% after 1010 cycles, respectively.

• 조명전기설비학회논문지
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• 제27권3호
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• pp.107-112
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• 2013

Cu(In,Ga)$Se_2$ (CIGS) thin films were annealed on molybdenium/sodalime glass substrates of $300{\times}300mm^2$ by rapid thermal processing (RTP) with 2-step rising-temperature times in $N_2$ ambient. Morphological property, structural characteristics and chemical composition of the precursor of CIGS thin films were influenced directly with a change of $1^{st}$-step rising-temperature time in RTP whereas there is no significant difference with the different $2^{nd}$-step rising-temperature time (final crystallization temperature). The shorter $1^{st}$-step rising-temperature time in RTP obtained the higher photovoltaic cell efficiency from 7.469% to 8.479% even though the ideal composition in CIGS thin films could not be accoplished in this study.

• 전자공학회논문지A
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• 제29A권8호
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• pp.49-55
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• 1992

We Have investigated the properties of the titanium nitrite films widely used in VLSI devices as diffusion barrier in Al-based metallization. TiN films were formed by reactive sputtering from Ti target in Ar-N$_2$ mixtures, varying deposition parameters such as N$_2$ partial pressure, substrate temperature, power, and total pressure. All the samples received the heat treatment at 45$0^{\circ}C$ for 30 min. The resulting films are characterized by mechanical stylus($\alpha$-step), x-ray diffraction(XRD), scanning electron microscopy(SEM), and four point probe method. The Tin film properties strongly depend on the deposition condition. The stoichiometry and Ti deposition rate are critically affected by nitrogen partial pressure, and the resistivity, in particular, is dependent on both the substrate temperature and sputtering power.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.3-5
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• 2001

ZnO thin films are deposited on $SiO_2$/Si (111) substrate by RF magnetron sputtering. The two-step deposition method is proposed to enhance both the c-axis orientation and the resistivity of ZnO films. This method consists of the following two procedures: the 1 st-deposition for 30 min without oxygen at l00W and the 2nd-deposition with oxygen added in the range of $O_2/(Ar+O_2)=10{\sim}50%$. Effects of thermal treatment on the properties of ZnO films are systematically investigated.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.175.1-175.1
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• 2015

CuSn thin films were deposited by rf magnetron co-sputtering method with pure Cu and Sn metal targets with a variety of rf powers. CuSn thin films were studied with a surface profiler (alpha step), X-ray photoelectron spectroscopy (XPS), X-ray induced Auger electron spectroscopy (XAES), X-ray diffraction (XRD), and contact angle measurement. The thickness of CuSn thin films was fixed at $200{\pm}10nm$ and deposition rate was calculated by the measured with a surface profiler. From the survey XPS spectra, the characteristic peaks of Cu and Sn were observed. Therefore, CuSn thin films were successfully synthesized on the Si (100) substrate. The oxidation state and chemical environment of Cu and Sn were investigated with the binding energy regions of Cu 2p XPS spectra, Sn 3d XPS spectra, and Cu LMM Auger spectra. Change of the crystallinity of the films was observed with XRD spectra. Using contact angle measurement, surface free energy (SFE) and wettability of the CuSn thin films were studied with distilled water (DW) and ethylene glycol (EG).

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권7호
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• pp.308-314
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• 2005

The 2 GHz film bulk acoustic wave resonator(FBAR), one of the most necessary device of the next generation mobile communication system, consisted of solidly mounted resonator(SMR) structure using Brags reflector, was researched in this paper The FBAR applied SiO$_{2}$ and W had large difference of the acoustic impedance to reflector Al to electrode and ZnO to piezoelectric layer. Specially, the FBAR applied the two-step deposition method to improve the c-axis orientation and increase reproducibility of the fabrication device had good performance. The electrical properties of plasma such as impedance, resistance, reactance, $V_{pp},\;I{pp}$, VSWR and phase difference of voltage and current, was analyzed and measured by RF sensor with the variable experiment process factors such as gas ratio, RF power and base vacuum level about concerning the thickness, c-axis orientation, adhesion and roughness. The FBAR device about the optimum condition resulted reflection loss(S$_{11}$) of -17 dB, resonance frequency of 1.93 GHz, electric-mechanical coefficient(k$_{eff}$) of 2.38 $\%$ and Qualify factor of 580. It was seen better qualify than the common dielectric filter at present and expected on business to the filter device of 2 GHz bandwidth with the MMIC technology.

• 한국표면공학회지
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• 제29권5호
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• pp.415-423
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• 1996

Thin film technologies for fabricating SQUIDs involve etching and deposition procedures with the proper substrate materials and $YBa_2Cu_3O_{7-d}$ (YBCO) as the high $T_c$ superconductor. YBCO were prepared on various substrates of MgO, $SrTiO_3$, and $LaAlO_3$ by using off-axis magnetron sputtering methods and annealing in-situ. The parameters of film fabrication processes had been optimized to yield good quality films in terms of the critical temperature $T_c$ and the critical current density $J_c$. The optimized processes yielded $T_C$>90K along with $J_c$>$10_6A$$extrm{cm}^2$ at 77K and>$2\times10_7A/Cm^2$ at 5K. We fabricated step-edge type dc-SQUIDs and directly coupled magnetometers, producing step edges on MgO(100) substrates by etching with Ar-ion beam, depositing YBCO material on them, then patterning them by using ion-milling technique. Circuitizing washer-shape SQUIDs to possess a pair of step-edge junctions of 2-5$\mu$ line width with a high angle>$50^{\circ}C$ , we examined their I-V characteristics thoroughly and Shapiro steps clearly as we irradiate microwaves of 8-20 GHz frequency.

• 한국재료학회지
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• 제11권9호
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• pp.769-775
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• 2001

High quality PZT piezoelectric thin films were sputter- deposited on$ RuO_2$/$SiO_2$/Si substrates by using 2-step deposition method. As the first step, PZT seed layers were fabricated at a low temperature($475^{\circ}C$ ) to form a pure perovskite phase by reducing the volatility of Pb oxide. and then, as the second step, the PZT films were deposited at high temperatures ($530^{\circ}C$~$570^{\circ}C$) to reduce the defect density in the films. By this method, the pure perovskite phase was obtained at high deposition temperature range ($530^{\circ}C$~$570^{\circ}C$) and the superior electrical properties of PZT films were obtained on $RuO_2$substrate : 2Pr : 60$\mu$C/$\textrm{cm}^2$, $E_c: 60kV/cm, \;J_t: 10^{-6}A/cm^2\; at\; 250kV/cm$. The residual stress of PZT films fabricated by the 2-step deposition method was tensile and below 150MPa. It was attempted to control the residual stress in the PZT films by applying a negative bias to the substrate. As the amplitude of the substrate bias was increased, the residual tensile stress was slightly decreased, however, the ferroelectric properties of PZT films were degraded by ion bombardment.