Semiconductor devices have evolved from 2D planar FETs to 3D bulk FinFETs, with aggressive device scaling. Bulk FinFETs make it possible to suppress short-channel effects. In addition, the use of low-k dielectric materials as a vacuum gate spacer have been suggested to improve the AC characteristics of the bulk FinFET. However, although the vacuum gate spacer is effective, correlation between the vacuum gate spacer and the short-channel-effects have not yet been compared or discussed. Using a 3D TCAD simulator, this paper demonstrates how to optimize bulk FinFETs including a vacuum gate spacer and to suppress short-channel effects.

As a process to improve the insulation performance of VIs (Vacuum Interrupters), AC voltage conditioning is generally adopted by many manufacturers. Although the insulation performance is enhanced easily with AC Voltage conditioning, it has limitations when high recovery voltage is required due to high voltage rate or capacitive current switching. In particular, impurities such as oxides segregated on the electrode surface can be removed not by the energy level of the voltage conditioning but by the higher energy level achieved by the current conditioning process In this article, the current conditioning was carried out in various conditions and its validity was examined. The current conditioning was processed by changing the amplitude of applied current, arc time, the number of tests, and frequency. The insulation performance and the status of contact surface were checked as well. We concluded that as the applied charge quantity and the conditioning coverage area increase, the conditioning effect is much higher.

A variable vacuum capacitor (VVC), which is a variable element, is used to match impedance in plasma that changes with various impedance values, and its use is expanding with the rapid growth of the semiconductor business. Since VVCs have to secure insulation performance and vary capacitance within a compact size, electrode design and manufacturing are very important; thus, various technologies such as part design and manufacturing technology and vacuum brazing technology are required. In this study, based on the model of an advanced foreign company that is widely used for impedance matching in the manufacture of semiconductors and displays, a VVC that can realize the same performance was developed. The electrode part was designed, the consistency was confirmed through analysis, and the precision of capacitance was improved by designing a cup-type electrode to secure the concentricity of the electrode. As a result of the evaluation, all requirements was satisfied. We believe that self-development will be possible if satisfactory responses are received through evaluation by VVC consumers in the future.

Global warming is accelerating due to the use of fossil fuels that have been used continuously for centuries. Now, humankind recognizes its seriousness, and is conducting research on searching for eco-friendly and sustainable energy. In the field of solar energy, which is a kind of eco-friendly and sustainable, many studies are being conducted to enhance the output performance of the module. In this study, the output improvement for the shingled module structure was studied. In order to improve the output performance of the module, the thickness of the encapsulant was increased, and the lamination process conditions have been improved accordingly. After that, the crosslinking rate was analyzed, and the suitability of the lamination process conditions was judged using this. In addition, a peeling test was conducted to analyze the correlation between the adhesion of the encapsulant and the output performance of the module. Finally, the optimization for the encapsulant material and the lamination process conditions for high-power shingled modules was established, and accordingly, the market share of high-power shingled modules in the solar module market can be expected to rise.

The 22.9 kV vacuum interrupter (VI) built-in load bus switcher (LBS), which is most often used as a load switch for distribution, extinguishes the arc that occurs during normal load opening and closing and fault current interruption within the VI housing to quickly switch circuits. As a protective device for contact separation, the rated current is supplied in a normal state. When a fault current flows due to a fault or an accident in the power system, the contact is disconnected in a vacuum state to block the fault current. In this study, in order to design the optimal VI, the heat dissipation characteristics of VI according to the center electrode distance 0/1/2/3 cm were analyzed by applying the finite element method, and the results were reflected to improve the structure of the VI.

CNT fiber has been in the spotlight as a conductor, but the conductivity of CNT fibers do not match that of CNT. This study reveals that the conductivity of CNT fiber can be improved by depositing Al/Cu through vacuum evaporation. Cu is commonly used for deposition on CNT fibers. But low bonding strength of the interface between CNT and Cu could be a disadvantage. To overcome this, Al was deposited on the CNT fiber for forming aluminum carbide islands to increase the interfacial bonding strength. The conductivity characteristics were improved as the deposition time increased. The resistance was measured as a function of temperature, demonstrating that the temperature coefficient of resistance (TCR) is improved to be 241 ppm/℃ in comparison with that of as-received CNT fibers at -1,251 ppm/℃, when the CNT fibers are deposited with Al and Cu, respectively, for 90s and for 540s.

Copper-chromium alloys have been used as contact materials of vacuum interrupters in circuit breakers, but new materials with highly stable performance are required to break the high voltage and high current barrier due to the recent increase in breaking capacity. In this paper, a new contact material was fabricated from a ternary alloy instead of existing Cu-Cr alloys. Its breaking performance and endurance were verified from a synthetic test and compared with that of various contact materials. The test results verified that the breaking performance of the new contact material was excellent.

In this study, we tried finding new materials to improve the stain resistance properties of polymer insulating materials. Using the filtered vacuum arc source (FVAS) with a graphite target source, DLC thin films were deposited on silicon and polymer insulator substrates depending on their thickness to confirm the surface properties, physical properties, and structural properties of the thin films. Subsequently, the possibility of using a DLC thin film as a protective coating material for polymer insulators was confirmed. DLC thin films manufactured in accordance with the thickness of various thin films exhibited a very smooth and uniform surface. As the thin film thickness increased, the surface roughness value decreased and the contact angle value increased. In addition, the elastic modulus and hardness of the DLC thin film slightly increased, and the maximum values of elastic modulus and hardness were 214.5 GPa and 19.8 GPa, respectively. In addition, the DLC thin film showed a very low leakage current value, thereby exhibiting electrical insulation properties.

TiN (titanium nitride) films were prepared using the RF magnetron sputtering technique. The films were deposited by pure N₂ plasma sputtering. Their mechanical properties, such as nano-indentation hardness, friction coefficient, and surface wettability, have been investigated. X-ray diffraction (XRD) studies revealed that the orientation of TiN_X films changed towards the (111) orientation with decreasing working pressure due to a strong compressive stress during deposition. The strongest TiN (111) orientation was found when the film was deposited at a working pressure of 1 Pa. This film showed the largest hardness (16 GPa) and smallest friction coefficient (0.17) among the studied samples. Moreover, this film was found to be accompanied by a water-repellent surface with water contact angle more than 100°.

Recently, macroporous ceramic materials with high electrical conductivity and mechanical strength are urgently needed for semiconductor and display manufacturing devices. In this work, we obtained electro-conducting macroporous aluminosilicate ceramics having surface resistivity of 108~1,010 ohm by dispersing electro-conducting carbon in ceramic matrix. By addition of 0.5~3.0 wt% frit glass, chemical bonding between grains was strengthened, and flexural strength was enhanced up to 160 MPa as a result. We evaluated the characteristics of present ceramics as vacuum chuck module for liquid crystal display display manufacturing devices.

One of the important issues for fabricating the microelectronic display devices such as FED, PDP, and VFD is to obtain a high vacuum level inside the panel. In addition, sustaining the initial high vacuum level permanently is also very important. In the conventional packing technology using a tabulation method, it is not possible to obtain a satisfiable vacuum level for a proper operation. In case of FED, the poor vacuum level results in the increase of operating voltage for electron emission from field emitter tips and an arcing problem, resultantly shortening a life time. Furthermore, the reduction of a sealing process time in the PDP production is veryimportant in respect of commercial product. The most probable method for obtaining the initial high vacuum level inside the space with such a miniature and complex geometry is a vacuum in-line sealing which seals two glass plates within a high vacuum chamber. The critical solution for the vacuum sealing is to develop a frit glass to avoid the bubbling or crack problems during the sealing process at high temperature of about 400℃ under the vacuum environment. In this study, the suitable frit power was developed using a mixture of vitreous and crystalline type frit powders, and a vacuum sealed CNT FED with 2 inch diagonal size was fabricated and successfully operated.

A vacuum Interrupter (VI), a core part that composes the breaking part of medium-voltage vacuum circuit breaker (VCB), has the excellent insulation performance and arc-extinguishing capability. SF6 gas had been used for the external insulation of VIs since the dielectric strength of SF6 gas is superior to that of other insulation gases. However, because of environmental problems related with global warming, a solid-insulated technology was recently researched. The functionally graded material (FGM), as changing spatially the distribution of the relative permittivity inside an insulator, can reduce the electric field stress at the specific region. Especially, the external insulation performance of the VI with the molded FGM insulator is greatly improved as compared with that of the existing VI or the VI with a new external shield. In this paper, the effectiveness of this FGM insulator is verified by the numerical simulation.

Chip on board type white light emitting diode on metal core printed circuit board with high thixotropy silicone is fabricated by vacuum printing encapsulation system. Encapsulant is chosen by taking into account experimental results from differential scanning calorimeter, shearing strength, and optical transmittance. We have observed that radiant flux and package efficacy are increased from 336mW to 450mW and from 11.9 lm/W to 36.2 lm/W as single dome diameter is varied from 2.2 mm to 2.8 mm, respectively, Double encapsulation structure with 2.8 mm of dome diameter shows further significant enhancement of radiant flux and package efficacy to 667mW and 52.4 lm/W, which are 417mW and 34.8 lm/W at single encapsulation structure, respectively.

Room temperature powder spray in vacuum process, so called Aerosol deposition (AD) is a room temperature (RT) process to fabricate thick and dense ceramic films, based on collision of solid ceramic particles. This technique can provide crack-free dense thin and thick films with thicknesses ranging from sub micrometer to several hundred micrometers with very fast deposition rates at RT. In addition, this technique is using solid particles to form the ceramic films at RT, thus there is few limitation of the substrate and easy to control the compositions of the films. In this article, we review the progress made in synthesis of piezoelectric thin/thick films, multi-layer structures, NTC thermistor thin/thick films, oxide electrode thin films for actuators or sensor applications by AD at Korea Institute of Materials Science (KIMS) during the last 4 years.

An optical lens is usually produced in the manner of high temperature compression molding with tungsten carbide alloy molding cores, it is necessary to develop and study technology for super-precision processing of molding cores and coating the core surface. As main methods used in surface improvement technologies using thin film, DLC present high hardness, chemical stability, and outstanding durability of abrasion to be extensively applied in various industrial fields. In this study, the effect of DLC coating of a thin film by means of the FVAS (filtered vacuum arc source) analyzed the characteristics of thin film. Surface roughness before and after DLC coating was measured and the result showed that the surface roughness was improved after coating as compared to before coating. In conclusion, it was observed that DLC coating of the ultra hard alloy core surface for molding had an effect on improving the surface roughness and shape of the core surface. It is considered that this will have an effect on improving abrasion resistance and the service life of the core surface.

Ga doped ZnO (GZO)/Cu bi-layer films were deposited with RF and DC magnetron sputtering on glass substrate and then the effect of post deposition annealing temperature on the structural, optical and electrical properties of the films was investigated. The post deposition annealing process was conducted for 30 minutes in gas pressure of 1×10-3 Torr and the annealing temperatures were 150 and 300℃. With increasing annealing temperature, GZO/Cu films showed an increment in the prefer orientation of ZnO (002) diffraction peak in the XRD pattern and the optical transmittance in a visible wave region was also increased, while the electrical sheet resistance was decreased. The GZO/Cu films annealed at 300℃ showed the highest optical transmittance of 70% and also showed the lowest electrical resistance of 85 Ω/□ in this study.

Effect of pump combinations on the vacuum characteristics of vacuum system was simulate d for optimum design of system. In this investigation, the feasibility of modelling mechanism for VacSim(Multi) simulator was proposed. Simulation results of various pumping combinations showed the possibilities and reliabilities of simulation for the performance of vacuum system in specific semiconductor processing. Simulation of roughing pump presented the expected pumping behaviors based on commercial specifications of employed pumps. Application of booster pump exhibited the high pumping efficiency for middle vacuum range. Combinations of optimum backing pump for diffusion and turbo vacuum system were obtained. And, the predictable characteristics of process application of both simulated systems were also acquired.