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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Vacuum Society
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Journal DOI :
The Korean Vacuum Society
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Volume & Issues
Volume 10, Issue 4 - Dec 2001
Volume 10, Issue 3 - Oct 2001
Volume 10, Issue 2 - Jul 2001
Volume 10, Issue 1 - Apr 2001
Selecting the target year
Quasi-quantitative estimation on backstreaming characteristics of a turbomolecular pump
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 1~9
Pumping characteristics of a turbomolecular pump are influenced by interrelations of the down-stream and upstream pumping speeds (transmission probabilityxaperture conductance), and of gas flow rates (pumping speedxentrance pressure) in two directions. The pumping speed, one of the most important items characterized the performance of a pump, is given by dividing the net flow rate, that is, the difference between the counter flow rates by the pressure at the pumping port. The maximum compression ratio is defined as the ratio of the downstream pumping speed to the upstream one. Because these directional characteristics affect each other and are functions of the pressures of both sides, it is difficult to distinguish the relevant factors. However, quasi-quantitative analyses on them can be done if considering carefully the results of measuring the pumping speed and the maximum compression ratio.
Residual gas analysis of small cavity for emissive flat panel display
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 9~15
The total pressure and partial pressure of small cavity for flat panel display have been successfully measured by using an ultra-high vacuum chamber with mass spectrometer. The total pressure in the panel was in the range of
Torr and the major partial pressure affecting increase in total pressure were those of Ar,
and He. The baking temperature during evacuation process was very important for high-vacuum package, the total pressure and partial pressure of
were decreased as the increase of baking temperature.
Optical properties of
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 16~21
Optical properties of
quaternary semiconductor single crystals grown by the chemical transport reaction method were investigated. The analysis of the X - ray powder diffraction measurements showed that these crystals have a wurtzite structure with lattice constants a = 4.357
, c = 7.380
and a = 4.885
, c = 7.374
. The direct band gap at 298K, obtained from the optical absorption measurement, is found to be 1.21 eV for
and 1.02 eV for
. The shrinkage of the band gap due to Co-doping is observed and is about 190 meV, We observed four absorption bands of
ions in two near infrared regions of optical absorption spectra of
. These absorption bands were assigned as due to electronic transitions between the split energy levels of
crystal field under spin-orbit interactions.
Microstructural ananalysis of AlN thin films on Si substrate grown by plasma assisted molecular beam epitaxy
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 22~26
Microstructures of AlN thin films on Si substrates grown by plasma assisted molecular beam epitaxy were analyzed with various growth temperatures and substrate orientations. Reflection high energy electron diffraction (RHEED) patterns were checked for the in-situ monitoring of the growth condition. X-ray diffraction(XRD), double crystal X-ray diffraction (DCXD), and transmission electron microscopy/diffraction (TEM/TED) techniques were employed to characterize the microstructure of the films after growth. On Si(100) sub-strates, AlN thin films were grown mostly along the hexagonal c-axis orientation at temperature higher than
. On the other hand the AlN films on Si(111) were epitaxially grown with directional coherencies in AlN(0001)/Si(111), AlN(1100)/Si(110), and AlN(1120)/Si(112). The microstructure of AlN thin films on Si(111) substrates, with a full width at half maximum of almost 3000 arcsec at 2
, showed that the single crystal films were grown, even if they includ a lot of crystal defects such as dislocations and stacking faults.
Dielectric passivation effects on the electromigration phenomena in Al-1%Si thin film interconnections
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 27~30
Electromigration Phenomena in Al-1%Si thin film interconnections under DC and PDC conditions were investigated. Thin film interconnections with
dielectric passivation layer were formed by a standard photolithography process method and test line lengths were 100, 400, 800, 1200, and 1600
. The current density of
was stressed in Al-1%Si thin film interconnections under DC condition. The current density of
was also applied under PDC condition at the frequency of 1 Hz with the duty factor of 0.5. The electromigration resistance of PSG/SiO2 dielectric passivation test line was stronger than
dielectric passivation test line. The lifetime under PDC was 2-4 times longer than DC condition. As the thin film interconnection line increased, the lifetime decreased and saturated over the critical length. Failure patterns by an electromigration were dominated by void-induced electrical open and hillock-induced electrical short.
Secondary electron emission characteristics of a thermally grown
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 31~36
The secondary election emission (SEE) yields for the thermally grown
thin layers were measured by varying the thickness of the
layer and the primary current.
thin layers were thermally grown in a furnace at
, whose thickness varied to be 5.8 nm, 19 nm, 43 nm, 79 nm, 95 nm, and 114 nm. When the
layers were thinner than 43 nm, it was found that SEE curves followed the universal curve. However, for samples with a
layer thicker than 79 nm, the SEE curves exhibited two maxima and the values of SEE yields were reduced. Additionally, as the current of primary electrons increased, the SEE yields were reduced. In this experiment, the maximum value of the SEE yield for
layers was obtained to be 3.35 when the thickness of
layer was 19 nm, with the primary electron energy 300 eV and the primary electron current 0.97
. The penetration and escape depth of an electron in the
layers were calculated at the primary electron energy for the maximum value of the SEE yield and from these depths, it was calculated that the thickness of the
Adhesion improvement between metals and fluoropolymers by ion assisted reaction
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 37~43
Polyvinylidenefluoride and Polytetrafluoroethylene have been irradiated by 1 keV Ar+ ion beam in an
environment. Hydrophilic functional groups (such as -(C-O)-,-(C=O)-,-(C=O)-O- and so on) were formed on fluoropolymers. Contact angles of water to PVDF were reduced from
. Re-increase of contact angle was originated from carbonization phase in case of high dose irradiation above
. Contact angles to PTFE decreased at low dose irradiation and were exaggerated to about
due to cone type surface at high dose irradiation. Hydrophilic functional groups have played an important role on adhesion between metal and fluoropolymers by acid-base interaction and chemical bond formation. Adhesion of Pt/PVDF was enhanced by acid-base interaction because Pt is inert metal. Chemical bond formation between Cu and PTFE could enlarge the adhesion strength of Cu/PTFE.
Electrical properties of metal-oxide-semiconductor structures containing Si nanocrystals fabricated by rapid thermal oxidation process
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 44~50
Metal oxide semiconductor (MOS) structures containing nanocrystals are fabricated by using rapid thermal oxidations of amorphous silicon films. The amorphous films are deposited either by electron beam deposition method or by electron beam deposition assisted by Ar ion beam during deposition. Post oxidation of e-beam deposited film results in relatively small hysteresis of capacitance-voltage (C-V) and the flat band voltage shift,
is less than 1V indicative of the formation of low density nanocrystals in
/Si interface. By contrast, we observe very large hysteresis in C-V characteristics for oxidized ion-beam assisted e-beam deposited sample. The flat band voltage shift is larger than 22V and the hysteresis becomes even broader as increasing injection times of holes at accumulation condition and electrons at inversion condition. The result indicates the formation of slow traps in
/Si interface which might be related to large density nanocrystals. Roughly estimated trap density is
. Such a large hysteresis may be explained in terms of the activation of adatom migration by Ar ion during deposition. The activated migration may increase nucleation rate of Si nuclei in amorphous Si matrix. During post oxidation process, nuclei grow into nanocrystals. Therefore, ion beam assistance during deposition may be very feasible for MOS structure containing nanocrystals with large density which is a basic building block for single electron memory device.
Effects of oxygen partial pressure during sputtering on texture and electrical properties of
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 51~56
thin films as insulator for MFISFET (Metal-ferroelectric-insulator- semiconductor-field effect transistor) were deposited by r.f. magnetron sputtering. Ar and
gas as the deposition gas were used and the effects of oxygen partial pressure during sputtering on texture and electrical properties of
thin films were evaluated. All
thin films deposited on p-type Si(100) substrate at
exhibited (200) preferred orientation. The films deposited with only Ar gas among various condition had highest preferred orientation but show large hysteresis characteristics in capacitance-voltage measurement due to relatively many charged paricles and roughness. Films show smooth surface state and good C-V characteristics with increasing oxygen partial pressure. It was thought that this trend in C-V characteristics was due to the amount of mobile ionic charge within
films. The composition of films show oxygen excess, that is, O/
ratio of films was 2.22~2.42 range and leakage current of films show
order at 100 kV/cm.
Electrochemical preparation of CdS nanowire arrays in anodic alumina templates
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 57~60
We prepared uniform CdS nanowire arrays ways with lengths up to 5
and diameters as small as 20 nm by electrochemically depositing the semiconductor directly into the pores of anodic alumina films from an electrolyte containing
and S in dimethyl sulfoxide. The nanowire arrays were characterized by scanning electron microscopy and X-ray diffraction. The deposited materials are composed mainly of hexagonal CdS with (100) preferential orientation.
Properties of Sol-gel
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 61~66
films were multicoated on the microscope slide glass and ITO-coated glass using a tungsten alkoxide type solution by the sol-gel deposition process. The effect of dipping and processing parameters on the structure, optical and electrochemical properties of the film were also investigated. Coating using alkoxide solution was very uniformed for low dipping speed of 0.005 m/s, but thickness variations across the sample became apparent for dipping speeds greater than 0.007 m/s. Electrochemical coloration experiments showed that films fired at lower temperatures color more easily than film fired to >
. Rutherford backscattering spectroscopy studies revealed that
ions were uniformly distributed throughout the
layer in the colored sample.
Optical properties of Zn-doped InGaN grown by MOCVD
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 67~71
Optical investigation on Zn-doped InGaN grown by MOCVD was performed by using the photoluminescence. Two different spectra related to Zn-acceptor-like centers occurred at room temperature, with broad emissions peaking at 2.81, and 2.60 eV, Specially, emissions interacted with phonon were observed at 2.81 eV where phonon energy was 92.5 meV From temperature dependent blue-band emissions of InGaN, we observe that the intensity in high energy region was quickly decreased more than that in low energy region with increased temperature, and the peak position at 2.81 eV was blue shift of about 18 meV, The blue-band emmissions would be originated from the transition related to the localized Zn complex centers.
Comparative Pixel Characteristics of ELA and SMC poly-Si TETs for the Development of Wide-Area/High-Quality TFT-LCD
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 72~80
In this paper, we present a systematic method of extracting the input parameters of poly-Si TFT(Thin-Film Transistor) for Spice simulations. This method has been applied to two different types of poly-Si TFTs such as ELA (Excimer Laser Annealing) and SMC (Silicide Mediated Crystallization) with good fitting results to experimental data. Among the Spice circuit simulators, the PSpice has the GUI(graphic user interface) feature making the composition of complicated circuits easier. We added successfully the poly-Si TFT model of AIM-Spice to the PSpice simulator, and analyzed easily to compare the electrical characteristics of pixels without or with the line RC delay. In the comparative results, the ELA poly-Si TFT is superior to the SMC poly-Si TFT in the charging time and the kickback voltage for the TFT-LCD (Thin Film Transistor-Liquid Crystal Display).
A study on surface photovoltage characteristics of
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 81~86
We have investigated surface photovoltage characteristics of InGaAs grown by metalorganic chemical vapor deposition (MOCVD) method on semi-insulating GaAs. The splitted SPV signals from the substrate and epilayer were observed. The band gap energy of InGaAs was about 1.376 eV, The In composition(x) was determined by Pan's composition formula. The photovoltage gradually decreases with increasing frequency. This is because the transfer of charge from the surface states reduces. From the temperature dependent SPV measurement, we obtained Varshni and temperature coefficients. In spectrum of etched sample at 300 K, the 'A' peak below
is related with residual impurity during sample growth.
Preparation and characterization of magnetic nanoparticles with two kinds of core/shell structures
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 87~92
Magnetic Fe-Co(C) nanocapsules and Fe-Co nanoparticles were prepared by arc-discharge in two kinds of atmospheres, i.e. methane and a mixture of (
+Ar), respectively. Characterization and magnetic properties of this two kinds of ultrafine particles were investigated systematically by means of X-ray diffraction, Mssbauer spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, energy disperse spectroscopy analysis, chemical analysis, oxygen determination and magnetization measurement. Effects of carbon element, decomposed from a methane atmosphere in carbon arc process, on phase structures, magnetic states and surface characterization were studied in comparison to that of Ar element. Two ultrafine particles showed a little difference in the weight ratio of (Fe/co) and the size for Fe-Co nanoparticles was about two times bigger than Fe-Co(C) nanocapsules. The saturation magnetization of Fe-Co (C) nanocapsules was about 8% higher than that of Fe-Co nanoparticles while their phase constitutions were similar. Although no carbon could be detected by XRD measurement because of extremely thin shells on the surfaces of the cores, it is still believed that they are carbon and oxygen layers.
UHV x-ray scattering system for surface structural studies
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 93~97
We introduce the structure and the capability of a UHV x-ray scattering system constructed for surface structural studies. The system consists of vacuum parts required for surface preparation and a vertical-horizontal diffractometer using the S2D2 geometry. To illustrate the capability of the system, we measured the 7
7 reconstruction peak of a Si (111) surface. The peak count rate was 216 counts/sec and the domain size of the 7
7 reconstruction was larger than 1600
. This demonstrates that the system is capable of providing surface structural information.
A study on the application of dichroic mirror for the improvement of luminance and luminous efficacy in an AC Plasma Display Panel
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 98~103
A new application of dirchroic mirror for the improvement of luminance and luminous efficacy in an AC-Plasma Display Panel (PDP) is suggested. Only about half of the Vacuum Ultraviolet (VUV) generated in the reflective PDP cell is used for the excitation of the phosphor. We are suggesting an idea of adopting a dichroic mirror which can reflect the VUV toward the phosphor which otherwise is absorbed by the front panel. The optical constants of the thin films of dirhroic mirror were determined from the photometric measurements through an iteration process of matching calculated and measured values of the reflectance and transmittance in the VUV wavelength region. From these results, we could design such a filter whose high reflection zone is centered at 147nm by a computer simulation accurately. The 147nm VUV is radiated from Xenon 3Pl state which is dominantly used to activate the phosphor in the PDP cell. The dichroic mirror was made with an electronbeam evaporator and its reflectance was measured by a reflectometer. We confirmed the usefulness of the dichroic mirror for the improvement of efficiency with experiments done by test panels. The panel with mirror shows improved luminance and luminous efficacy by 20∼30％.
Effect of boron doping on the chemical and physical properties of hydrogenated amorphous silicon carbide thin films prepared by PECVD
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 104~111
B-doped hydrogenated amorphous silicon carbide (a-SiC:H) thin films were prepared by plasma-enhanced chemical-vapor deposition in a gas mixture of
. Physical and chemical properties of a-SiC:H films grown with varing the ratio of
were characterized with various analysis methods including scanning electron microscopy (SEM), X-ray diffractometry (XRD), Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, secondary ion mass spectroscopy (SIMS), UV absorption CH_4spectroscopy and electrical conductivity measurements. With the B-doping concentration, the doping efficiency and the micro-crystallinity were decreased and the film became amorphous when
. The addition of
gas during deposition decreased the H content in the film by lowering the quantity of Si-C-H bonds. Consequently, the optical band gap and the activation energy of a-SiC:H films were decreased with increasing the B-doping level.
A study on the characteristics of axially magnetized capacitively coupled radio frequency plasma
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 112~118
Magnetic field is commonly used in low temperature processing plasmas to enhance the performance of the plasma reactors. E
B magnetron or surface multipole configuration is the most popular. However, the properties of capacitively coupled rf plasma confined by axial static magnetic field have rarely been studied. With these background, the effect of magnetic field on the characteristics of capacitively coupled 13.56 MHz/40 KHz argon plasma was studied, Ion saturation current, electron temperature and plasma potential were measured by Langmuir probe and emissive probe. At low pressure region (~10 mTorr), ion current increases by a factor of 3-4 due to reduction of diffusion loss of charged particles to the wall. Electron temperature slightly increases with magnetic field for 13.56 MHz discharge. However, for 40 KHz discharge, electron temperature decreased from 1.8 eV to 0.8 eV with magnetic field. It was observed that the magnetic field induces large temporal variation of the plasma potential. Particle in cell simulation was performed to examine the behaviors of the space potential. Experimental and simulation results agreed qualitatively.
Measurement of hydrogen content in a-C:H films prepared by ECR-PECVD
Journal of the Korean Vacuum Society, volume 10, issue 1, 2001, Pages 119~126
Hydrogenated amorphous carbon (a-C:H) films were deposited by ECR-PECVD (electron cyclotron resonance-plasma enhanced chemical vapor deposition) method with deposition conditions such as ECR plasma source power, gas composition of methane and hydrogen, deposition time and substrate bias voltage. The hydrogen content in the films has been measured by ERDA (elastic recoil detection analysis) using 2.5 MeV
ion beam. From the results of AES (Auger electron spectroscopy), RBS (Rutherford backscattering spectrometry) and ERDA, the composition elements of deposited film were confirmed the carbon atom and the hydrogen atom. It was observed by FTIR (Fourier transform infrared) that the hydrogen contents in the film varied according to the deposition conditions. In deposition condition of substrate bias voltage, the hydrogen contents were decreased remarkably because the amount of dehydrogenation in films was increased as the substrate bias voltage increased. In the rest deposition conditions, the hydrogen contents in the film were measured in the range 45~55%.