• Solar Energy
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• v.5 no.2
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• pp.46-53
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• 1985

Hydrogenated amorphous silicon solar cells which are fabricated by photo-chemical vapor deposition (photo-CVD) system has been investigated. In the photo-CVD system which consists of three separate reaction chambers, low-pressure mercury lamp has been used as a light source. The main reactant ($Si_2H_6/He$) gases which are premixed with a small amount of mercury vapor in a mercury-vaporizer kept at $50^{\circ}C$ have been used. Using $C_2H_2$ and $SiH_2(CH_3)_2$ as the carbon source, p-type wide band gap a-SiC:H films have been obtained. The result has been found that the undoped layers of the pin/substrate solar cells are influenced by the residual impurities, such as phosphorus and boron during the deposition process. By minimizing the effect of the impurities in the i-layer and optimizing conditions at the p-layer and p/i interface, the energy conversion efficiency of 9.61 % under AM-1 ($100mW/Cm^2$) has been achieved for pin/substrate solar cells illuminated through their p-layers, using the three separate reaction chamber apparatus. It is expected that a-SiC:H solar cells with the energy conversion efficiency over 10% have been fabricated by Photo-CVD method.

• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.533-538
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• 2013

Silicon carbide (SiC) materials are typical ceramic materials with a wide range of uses due to their high hardness and strength and oxidation resistance. In particular, due to the corrosion resistance of the material against acids and bases including the chemical resistance against ionic gases such as plasma, the application of SiC has been expanded to extreme environments. In the SiC deposition process, where chemical vapor deposition (CVD) technology is used, the reactions between the raw gases containing Si and C sources occur from gas phase to solid phases; thus, the merit of the CVD technology is that it can provide high purity SiC in relatively low temperatures in comparison with other fabrication methods. However, the product yield rarely reaches 50% due to the difficulty in performing uniform and dense deposition. In this study, using a computational fluid dynamics (CFD) simulation, the gas velocity inside the reactor and the concentration change in the gas phase during the SiC CVD manufacturing process are calculated with respect to the gas velocity and rotational speed of the stage where the deposition articles are located.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1628-1630
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• 2000

Vertically aligned multiwalled carbon nanotubes are grown on silicon oxide substrate at 950$^{\circ}C$ by thermal chemical vapor deposition using $C_{2}H_2$. Three catalytic metals such as iron(Fe), cobalt (Co), and nickel(Ni) are used as catalyst, we found that the growth rate of carbon nanotubes for three catalyst particles are in an order of Fe > Ni > Co. All carbon nanotubes are revealed to have bamboo structure with no encapsulated catalytic particles, the diameter of carbon nanotubes depend on the catalyst, the tip and the compartment sheets of bamboo structure also depend on the shape of catalytic particles.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.12
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• pp.591-596
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• 2006

we have been developed on the ultra high concentration ozone generator system which is the core technology in the realization of the semiconductor photoresist strip process using the ozone-vapor chemistry. The proposed ozone generator system has the structure of the surface discharge type which adopt the high purity ceramic dielectric tube. We investigate the performance of the proposed ozone generator system experimentally and the results show that the system has very high ozone concentration characteristics of $19.7[wt%/O_2]$ at the flow rate of $0.3[{\ell}/min]$ of each discharge cell. As a result of the silicon wafer photoresist strip test, we obtained the strip rate of about 400[nm/min] at the ozone concentration of $16[wt%/O_2]$ and flow rate of $8[{\ell}/min]$. So, we confirmed that it's possible to use the proposed high concentration ozone generator system for the ozone-vapor photoresist strip process in the semiconductor and FPD industry.

• Safety and Health at Work
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• v.12 no.3
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• pp.403-415
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• 2021

Background: This study aimed to assess the possibility of benzene exposure in workers of a Korean semiconductor manufacturing company by reviewing the issued patents. Methods: A systematic patent search was conducted with the Google "Advanced Patent Search" engine using the keywords "semiconductor" and "benzene" combined with all of the words accessed on January 24, 2016. Results: As a result of the search, we reviewed 75 patent documents filed by a Korean semiconductor manufacturing company from 1994 to 2010. From 22 patents, we found that benzene could have been used as one of the carbon sources in chemical vapor deposition for capacitor; as diamond-like carbon for solar cell, graphene formation, or etching for transition metal thin film; and as a solvent for dielectric film, silicon oxide layer, nanomaterials, photoresist, rise for immersion lithography, electrophotography, and quantum dot ink. Conclusion: Considering the date of patent filing, it is possible that workers in the chemical vapor deposition, immersion lithography, and graphene formation processes could be exposed to benzene from 1996 to 2010.

• Journal of the Semiconductor & Display Technology
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• v.16 no.3
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• pp.1-7
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• 2017

Multi-wafer planetary type chemical vapor deposition reactors are widely used in thin film growth and suitable for large scale production because of the high degree of growth rate uniformity and process reproducibility. In this study, a two-dimensional model for estimating the effect of the gap between satellite and wafer on the wafer surface temperature distribution is developed and analyzed using computational fluid dynamics technique. The simulation results are compared with the results obtained from an analytical method. The simulation results show that a drop in the temperature is noticed in the center of the wafer, the temperature difference between the center and wafer edges is about $5{\sim}7^{\circ}C$ for all different ranges of the gap, and the temperature of the wafer surface decreases when the size of the gap increases. The simulation results show a good agreement with the analytical ones which is based on one-dimensional heat conduction model.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.35-39
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• 2023

Silicon oxide thin films have been deposited by plasma-enhanced chemical vapor deposition in SiH4 and N2O plasma along the variation of the gas flow ratio. Optical emission spectroscopy was employed to monitor the plasma and ellipsometry was employed to obtain refractive index of the deposited thin film. The atomic ratio of Si, O, and N in the film was obtained using XPS depth profiling. Fourier Transform Infrared Spectroscopy was used to analyze structures of the films. RI decreased with the increase in N2O/SiH4 gas flow ratio. We noticed the increase in the Si-O-Si bond angles as the N2O/SiH4 gas flow ratio increased, according to the analysis of the Si-O-Si stretching peak between 950 and 1,150 cm-1 in the wavenumber. We observed a correlation between the optical emission intensity ratio of (ISi+ISiH)/IO. The OES intensity ratio is also related with the measured refractive index and chemical composition ratio of the deposited thin film. Therefore, we report the added value of OES data analysis from the plasma related to the thin film characteristics in the PECVD process.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1737-1739
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• 2004

Diamond-like carbon (DLC) films were prepared with RF-PECVD (Plasma Enhanced Chemical Vapor Deposition) method on coming glass and silicon substrates using methane ($CH_4$) and hydrogen ($H_2$) gases. We examined the effects of $CH_4$ to $H_2$ ratios on tribological and optical properties of the DLC films. The structure and surface morphology of the films were examined using Raman spectroscopy and atomic force microscopy (AFM). The hardness of the DLC film was measured with nano-indentor. The optical properties of DLC thin film were investigated by UV/VIS spectrometer and ellipsometry. And also, solar cells were fabricated using DLC as antireflection coating before and after coating DLC on silicon substrate and compared the efficiency.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.2
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• pp.56-59
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• 2001

Thin films of hydrogenated amorphous silicon (a-Si : H) of different compositions were deposited on Si(100) wafer and glass by RF plasma-enhanced chemical vapor deposition (PECVD). In the present work, we have investigated the effect of the If. power on the properties, such as optical band gap, transmittance and crystallinity, of crystalline silicon thin films. Raman data show that the material consists of an amorphous and crystalline phase for the co-presence of two peaks centered at 480 and 520cm$^{-1}$. X-ray spectra confirmed of crystallites with (111) orientation at 300w The transmittance of thin films was measured by UV-VIS spectrophotometer. In addition, Si-H chemical bondings were studied by Fourier Transform Infrared (FT-IR) spectroscopy.

• Journal of the Korean Ceramic Society
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• v.52 no.4
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• pp.284-289
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• 2015

This study examined carbon layer coating on silicon carbide (SiC) fibers by utilizing solid-state and wet chemistry routes to confer toughness to the fiber-reinforced ceramic matrix composites, as an alternative to the conventional pyrolytic carbon (PyC) interphase layer. Electrophoretic deposition (EPD) of carbon black nanoparticles using both AC and DC current sources, and the vacuum infiltration of phenolic resin followed by pyrolysis were tested. Because of the use of a liquid phase, the vacuum infiltration resulted in more uniform and denser carbon coating than the EPD routes with solid carbon black particles. Thereafter, vacuum infiltration with controlled variation in phenolic resin concentration, as well as the iterations of infiltration steps, was improvised to produce a homogeneous carbon coating having a thickness of several hundred nanometers on the SiC fiber. Conclusively, it was demonstrated that the carbon coating on the SiC fiber could be achieved using a simpler method than the conventional chemical vapor deposition technique.