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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Vacuum Society
Journal Basic Information
Journal DOI :
The Korean Vacuum Society
Editor in Chief :
Volume & Issues
Volume 8, Issue 4B - Dec 1999
Volume 8, Issue 4A - Nov 1999
Volume 8, Issue 3B - Aug 1999
Volume 8, Issue 3A - Aug 1999
Volume 8, Issue 2 - Mar 1999
Volume 8, Issue 1 - Feb 1999
Selecting the target year
Asay of the fabrication technology of the KSTAR vacuum vessel mockup
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 391~396
KSTAR vacuum vessel mockup was fabricated by Korea Heavy Industries. The fabrication technology chosen for the mockup is introduced and assessed in this paper. KSTAR vacuum vessel is a huge vacuum chamber of 52 cubic meters never built in this country. Through the experiency of the KSTAR mockup fabrication, welding methods for obtaining both ultra high vacuum and structural integrity of the large vacuum chamber are extracted. The fabrication and assembly techniques for the complicated structure composed of reinforced ribs, double walls and various ports are also developed. A nondestructive test on the welding spot was performed and the results show that no major leaks violating the criterion were found. The one of the main objectives of the mockup fabrication is to measure the dimensions of the structure before and after fabrication, which plays an important role in the fabrication and the assembly. By assaying the problems occurred during mockup fabrication, the KSTAR mockup will provide the techniques for the fabrication of the main vacuum vessel.
Baking analysis of the KSTAR vacuum vessel and plasma facing components
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 397~402
The base pressure of the vacuum vessel of KSTAR tokamak is to be ultra high vacuum,
, to produce a clean plasma with low impurity concentrations. For this purpose, vessel and plasma facing components need to be baked up to
respectively to remove impurities from the plasma-material interaction surfaces. Here the required heating power to be supplied for baking has been calculated according to pre-assumed different temperature profiles (baking scenario and proper baking plan for KSTAR tokamak has been proposed. Mass flow rate and temperature of nitrogen gas for baking has also been calculated.
A study of surface states in Ar plasma exposed InP measured by photoreflectance
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 403~409
The surface state of Ar plasma-exposed Fe doped SI-InP have been investigated by photoreflectance (PR). From Ar plasma-exposed InP with 30 W for 10sec, the PR signals include a peak
that is located at 1.336 eV. We think that this peak was originated shallow level related to
. And we compared this level with the level obtained by surface photovoltage spectroscopy (SPV) measurement. The result of the PR agrees well with that from SPV. Additionally, Ar plasma induced phosphorus vacancy is related to shallow level. Therefore, the change of surface electric field are attributed to the shallow level. This level is caused by the existence of phsophorus vacancy on InP surface.
Analysis of electron emission mechanism in surface conduction electron emission displays
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 410~416
It is confirmed that the cause of anode current in SEDs (surface conduction electron emission displays) is the inertial force of electron emitted from the cathode surface in the calculation of electron trajectory. In the fissure of sub-micron, most of electrons emitted from the area of the cathode edge flow into the coplanar anode, while some electrons are emitted into the display surface by the current ratio of
. The later electrons are forced to fly into the display surface by the centrifugal force due to the curved electric field between top side surfaces near the fissure.
Investigation of field emission mechanism of undoped polycrystalline diamond films
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 417~424
In order to investigate field emission mechanism of undoped polycrystalline diamond films, diamond films with different structural properties were deposited by varying positive substrate bias and/or
concentration. When increasing
concentration and positive substrate bias voltage, nondiamond carbon content in diamond films increased. Increase of nondiamond carbon content with increasing substrate voltage is ascribed to increase of substrate and excess generation of
radicals. Field emission properties of undoped polycrystalline diamond films ere significantly enhanced with increasing nondiamond carbon content. For diamond films with a small amount of nondiamond carbon, electrons are emitted through diamond surface while for the films with a large amount of nondiamond carbon, electron emission occurs through diamond bulk as well as surface. From this study, depending on nondiamond carbon content two field emission mechanisms were suggested.
Growth and electrical properties of Pb(Zr, Ti)
thin films by sol-gel method
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 425~431
(PZT) thick films as an actuating material with conducting oxides,
(LSCO), have been fabricated by sol-gel method for Optical Micro-Electro-Mechanical System (MEMS) devices, in which PZT/LSCO/SiO2 structures were used. In order to improve the adhesion to LSCO solution in order to enhance the wetting behavior of a water-based LSCO precursor solution and further to improve the adhesion between LSCO and
layers. PZT films were made using 1-3 propanediol based precursor solution which has a high viscosity and a boiling point appropriate for thick film fabrication. In the precursor solution, Ti-propoxied and Zr-propoxied are partially substituted with acetylacetone to achieve the solution stability while maintaining reactivity. Crack free PZT films (0.8~1
) have been successfully fabricated at crystallization temperatures above
. Dielectric constants and dielectric losses of the PZT films were 900~1200and 2~5%, respectively. Piezoelectric constant
of the PZT films constrained by a substrate were 200pm/V at 100kV/cm.
Fabrication of He-Ne ellipsometer and in-situ measurement of effective density variation of
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 432~437
We have fabricated an in situ ellipsometer operating at He-Ne wavelength. It can be applied to the real-time, in-situ tracking of the ellisometric change which occurs during various sample treatments. As a rotating analyzer type, all optical elements and related parts are designed to share a common hollow-axis configuration, and hence the ellipsometer is compact in shape and simple in design. It is mountable on the spare ports of vacuum chamber with ease. Using this ellipsometer, we observed the effective density variation of previously grown
thin films by using electron beam evaporation. The packing density of the as-grown film was 82%. When exposed to atomsphere, the micro-void of the film was filled with water vapor. This water-filled
thin film was subject to heating/cooling cycles in vacuum and the ellipsometric variation versus temperature and cycling number was measured in real time using this in situ He-Ne ellipsometer.
The composition control of ITO/PET by plasma emission monitor
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 438~444
The characterization of the reactively sputtered ITO layer on the PET film has been studied. The PEM device has been used to determine the optimum stoichimetry through control of the amount of oxygen incorporated into the alloy target and the optimum operation conditions to produce films with the highest electrical conductivity and visible transparency. The PEP film was pre-treated under the plasma discharge condition to remove the adsorbed gases and to modify the surface morphology. The results revealed that by adjusting the flow rate of oxygen with the spectral intensity of indium target, the composition of plasma gas can be kept constant during the entire deposition period. The resistivity of ITO film obtained was fond to be about 37
, and the transmittance of visual range was about 86%.
INAs epitaxial layer growth for InAs Hall elements
S.M. Kim ;
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 445~449
We studied the properties of the InAs epitaxial layers grown of (100)-oriented GaAs (
tilted toward) by molecular beam epitaxy. From DCX (double-crystal x0ray), the better crystal quality was shown in InAs epitaxial layers on about 2500
GaAs epitaxial layers on GaAs, we obtained the high mobility of InAs epitaxy in As/In BEP ratio (1.2~2.0) from Hall effect measurement. The electron mobility increased as electron concentration increases, until Si cell temperature
. The mobility decreases as the Si cell temperature increases, at the temperature over
. We obtained the high mobility (1.10
104cm2/V.s) at Si electron concentration of
Optical properties of InAs quantum dots with different size
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 450~455
We present Photoluminescence (PL) and Atomic Force Microscopy (AFM) image on InAs quantum dots (QDs) having different size which grown by Molecualr Beam Epitaxy (MBE). For different size QDs, analysis of the AFM profiles show that the density of QDs was the maximum value
at 2.0 ML. In the spectra of QDs, it is found that the peak energy decreases with increasing dot size due to the effect of quantum confinement. Temperature dependence of PL intensities show that the PL is quenching and Red shift as the temperature increase. The FWHM range of 20K~180K is narrowing with increasing temperature. When temperature is over 180K, the line-width starts to in creases with increasing temperature. At last, temperature dependence of the integrated intensities were fit using the Arrehenius-type function for the activation energy. Fit value of the activation energy was increased with increasing QDs-size.
Laser micromachining of micron-size aperture for electron beam microcolumn application using the piezo-switched Nd:YAG laser
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 456~460
Experimental studies of laser micromachining on Mo diaphragm using piezo Q-switched Nd:YAZ laser have been performed. Application of miniaturized micorcolumn electron gun arrays as a potential electron beam lithography or portable mini-scanning electron microscope (SEM) application have recently extensively examined. The conventional microcolumn fabrication technique would give a limitation on the minimization of aberration, In this paper, we obtained 20~30
aperture of laser micromachining on Mo diaphragm using piezo Q-swithed Nd:YAG laser. The geometrical figures, such as the diameter and the preciseness of the drilled aperture are dependent upon the total energy of the laser pulse train, laser pulse width, and the diameter of laser spot in addition to the materials-dependent parameters.
A study on the fabrication of double rectangular spiral thin film inductor
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 461~464
Planar type thin film inductors have a potential for the application of miniaturized DC-DC converters. For those high current applications, the magnetic film with high current capability is required. The current capability of magnetic films is mainly determined from high saturation magnetization (4
) as well as large anisotropy field
. We fabricated a double rectangular spiral thin film inductor which consist of magnetic layer, coil and insulator. Highest inductance values as well as best frequency characteristics can be obtained from 5 MHz and quality factor exhibit about 7.
Development of spacer technology using glass to glass anodic bonding for FED
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 465~469
In this paper, spacer process for FED (Field Emission Display ) was developed with the glass to glass anodic bonding technology using Al film as an interlayer. Characteristics, current density-time curves and force of the anodic boding were measured on various thickness of Al film; 1000
. Holders for spacer were fabricated with photosensitive glass and (110) Si wafer by bulk micromachining. Spacers was formed on glass substrate by spacer glass to glass anodic bonding and an evacuated panel was fabricated to prove the potential of application for FED.
Growth of Zn-chalcogenide epilayers by hot-wall epitaxy and their structural properties
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 470~475
ZnS and ZnTe epilayers were grown on GaAs(100) GaP(100) substrates by hot-wall eitaxy. X-ray diffraction revealed that the epilayers have zinc-blende structure and were grown in (100) direction. The small values of the full width at half maximum (FWHM) of double crystal rocking curve (DCRC) showed high quality of the epilayers. From the thickness dependence of the FWHM of DCRC, the strain remaining in films is found to be due to the thermal expansion difference as well as due to the lattice mismatch.
A study on platinum dry etching using a cryogenic magnetized inductively coupled plasma
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 476~481
Characteristics of platinum dry etching were investigated in a cryogenic magnetized inductively coupled plasma (MICP). The problem with platinum etching is the redeposition of sputtered platinum on the sidewall. Because of the redeposits on the sidewall, the etching of patterned platinum structure produces feature sizes that exceed the original dimension of the PR size and the etch profile has needle-like shape . The main object of this study was to investigate a new process technology for fence-free Pt etching As bias voltage increased, the height of fence was reduced. In cryogenic etching, the height of fence was reduced to 20% at-
compared with that of room temperature, however the etch profile was not still fence-free. In Ar/
Plasma, fence-free Pt etching was possible. As the ratio of
gas flow is more than 14% of total gas flow, the etch profile had no fence. Chemical reaction seemed to take place in the etch process.
An analysis on the impurities generated by discharge in AC plasma display panel
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 482~489
AC PDP(P1asma Display Pane1)s use the mixture of inert gases to generate a discharge inside the display pixels. Impurities such as CO,
and OH inside discharge region may deteriorate the characteristics of PDP operation during long life time of PDP. Electro-negative gas such as CO can cause the sustain pulse amplitude to rise by attaching electrons which will play an important role in the earlier stage of the discharge. MgO film is used to protect the dielectric layer in AC PDP, and is in contact with the free space of display pixel where it is filled with the inert gas mixture. So, MgO film can be a main source of impurities. In this experiment, we observed the change of impurity generation of various MgO films which were deposited by different methods, by using QMS. (quadropole mass spectrometer) The main impurites were
, CO and
. And with the comparison of the TPD (temperature programmed desorption) result, it can be understood that impurity gases are generated by sputtering of MgO surface not by outgassing. Deposition method had effects on the characteristics of the impurity generation. The MgO film manufactured by e-beam evaporation generated more amount of impurity gases than the MgO films manufactured by sputtering or ion-plating. And also heat treatment of MgO film after deposition decreased the magnitude of impurity gas generation.
Study of plasma induced charging damage and febrication of
dual polysilicon gate using dry etch
Journal of the Korean Vacuum Society, volume 8, issue 4A, 1999, Pages 490~495
LOGIC device, the etch rate of NMOS polysilicons is different from that of PMOS polysilicons due to the state of polysilicon to manufacture gate line. To control the etch profile, we tested the ratio of
/HBr gas and the total chamber pressure, and also we reduced Back He pressure to get the vertical profile. In the case of manufacturing the gate photoresist line, we used Bottom Anti-Reflective Coating (BARC) to protect refrection of light. As a result we found that
gas is good to etch BARC, because of high selectivity and good photoresist line profile after etching BARC. in the results of the characterization of plasma damage to the antenna effect of gate oxide, NO type thin film(growing gate oxide in 0, ambient followed by an NO anneal) is better than wet type thin film(growing gate oxide in