• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.10
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• pp.106-112
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• 1990

The progress of oxidation of a porous silicon layer(PSL) was studied by examining the temperature dependence of the oxidation and the infrared absorption spectra. Thick OPSL(oxidized porous silicon layer). which has the same properties as thermal $SiO_{2}$ of bulk silicon, is formed in a short time by two steps wet oxidation of PSL at $700^{\circ}C$, 1 hr and $1100^{\circ}C$, 1 hr. Etching rate, breakdown strength of the OPSL are strongly dependent on the oxidation temperature, oxidation atmosphere. And its breakdown field was ${1\MV/cm^-2}$ MV/cm The oxide film stress was determined through curvature measurement using a dial gauge. During oxidation at temperature above $1000^{\circ}C$ in dry $O_{2}$, stress on the order of ${10^9}\dyne/{cm^2}{-10^10}\dyne/{cm^2}$ are generated in the OPSL.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.424-430
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• 1998

Film characteristics of thin ONO dielectric layers for MONOS (metal-oxide-nitride-oxide-semiconductor) EEPROM was investigated by AES, SIMS, TEM and AFM. The ONO films with different dimension of tunneling oxide, nitride, and blocking oxide were fabricated. During deposition of the LPCVD nitride films on tunneling oxide, this thin oxide was nitrized. When the blocking oxide were deposited on the nitride film, the oxygen not only oxidized the nitride surface, but diffused through the nitride. The results of ONO film analysis exhibits that it is made up of $SiO_2$(blocking oxide)/O-rich SiOxNy (interface)/ N-rich SiOxNy(nitride)/O-rich SiOxNy(tunneling oxide). In addition, the SiON phase is distributed mainly near the tunneling oxide/nitride and nitride/blocking oxide interfaces, and the $Si_2NO$ phase is distributed mainly at nitride side of each interfaces and in tunneling oxide.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.2
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• pp.38-45
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• 1997

In this paper, the three-dimensional stress effect of thermal oxide is simulated. We developed a three-dimensional finite element numerical simulator including three-dimensional adaptive mesh generator that is able to refine and eliminate nearby moving boundary of oxide, and oxidation solver with stress model. To investigate the behavior of thermal oxidation the simulations of thermal oxidation for island and hole structures are carried out assuming silicon wafer of <100> direction, temperature of $1000^{\circ}C$, oxidation time of 60min, wet ambient, initial oxide thickness of $300\AA$, and nitride thickness of $2, 000\AA$. The main effect of deformation at the corner area of oxide is due to distribution of oxidant, but the deformation of oxide is affected by the stressin theoxide. In the island structure which is the structure mostly covered with nitride and a coner is opended to oxidation, oxidation is reduced at the coner by compressive stress. In the hole structure which is the structure mostly opedned to oxide and a coner is convered with nitride, however, oxidation is increased at the coner by tensile stress.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.3
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• pp.25-34
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• 1981

Aluminum anodization method has been investigated for fabricating charge coupled device(CCD) with two-level aluminum gate structure. Al2O3 films were formed to a thickness of 400-500A, by anodizing aluminum with 30-35V of anode voltage for 2 hours using 2 % ammonium tartrate solution as an electrolyte. Breakdown voltage of these films were about 30 volts. Using above mentioned Al2O3 film as an insulator between two aluminum electrodes, CCD transversal low pass filter has been fabricated. CCD transversal low pass filter with 17 tap coefficients has shown 22 dB stop-band attenuation. The operating clock frequency range of the fabricated device was from 3 KHz to 100 KHz.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.385-399
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• 2000

Groundwater contamination caused by landfill leachate leads to various changes in aquifer environment according to the characteristics of incoming contaminants and aquifer geochemistry. These changes in aquifer environment are known to contribute to the natural attenuation phenomena of contaminants. The knowledge on changes in aquifer environment is necessary to determine the extent of groundwater pollution, to assess risk of the pollution, and to develop an appropriate remediation technologies. In this paper, the changes in aquifer environment caused by landfill leachate development of various redox zones-and the natural attenuation phenomena occurred in each redox zone are reviewed. From this review, an appropriate research direction and control action is presented for the groundwater pollutions caused by unsanitary landfills scattered across the nation.

• Journal of Soil and Groundwater Environment
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• v.7 no.1
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• pp.25-31
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• 2002

This study attempts to elucidate the possibility of treating landfill leachate by steelers' dust/${H_2}{O_2}$ system in a well-mixed batch reactor. Experiments were conducted to investigate the effects of operating variables such as pH, dust and ${H_2}{O_2}$ dosages and ${H_2}{O_2}$ injection method on the treatment efficiency, Contaminant concentrations were identified by TOC (Total Organic Carbon) analyzer. Experimental observations showed the possibility of steelers' dust as a catalytic reagent in the ${H_2}{O_2}$/dust system. The batch experiments showed that the optimal $H_2O$$_2$ and dust dosage, 20g/L dust. 2,000mg/L ${H_2}{O_2}$ removed about 75% of initial TOC concentration (250mg/1) within 60 min. And the TOC removal in the ${H_2}{O_2}$/dust system effectively proceeded only within a limited pH range of 3-4. The stealers' dust-catalyzed oxidative treatment of landfill leachate was more efficient compared with the $FeSO_2$catalyzed system (Fenton oxidation) for the removal rate and the cost.

• Journal of the Korean Wood Science and Technology
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• v.28 no.1
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• pp.71-79
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• 2000

Two linerboards consisting of corrugated board were coated with oxidized starch solutions to investigate the change of their properties and analyze the effect of coating on them. The coating of linerboards with oxidized starch resulted in improvement in the properties related to corrugated board properties by increasing fiber bonding and rigidity. The improvement of ring crush strength by coating was greater in inside linerboard than in outside linerboard. Burst index of linerboards rapidly increased with an initial increase of coating weight, but as the coating weight further increased, there was no increase in burst index. Coating on linerboards with oxidized starch at low coating weight improved stiffness of them. There were no significant changes in tearing resistance of linerboards by coating of oxidized starch. The coating resulted in increase in air resistance and sizing degree of linerboards.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.5
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• pp.473-478
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• 2016

In this paper, the MIS(: Metal-Insulator-Semiconductor) Capacitor with the nitrided-oxide by RTP are fabricated to investigate the carrier trap parameters due to avalanche electron injection. Two times turn-around phenomenon of the flatband voltage shift generated by the avalanche injection are observed. This shows that electron trapping occurs in the oxide film at the first stage. As the electron injection increases, the first turn-around occures due to a positive charge in the oxide layer. After further injection, the curves turns around once again by electron captured. Based on the experimental results, the carrier trapping model for system having multi-traps is proposed and is fitting with experimental data in order to determine trap parameter of nitrided-oxide.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.9
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• pp.1307-1312
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• 2013

In this paper, alkaline or acidic solution, in particular the principle of electrolysis to oxidize the metal surface to form a device isolation film is developed. In the past, mainly in the form of pulse voltage is applied to the anode only a unipolar method, but in this paper by using the H-bridge to the amount of the positive (+) voltage and the negative supply voltage, alternating voltage polarity devices were fabricated according to the characteristics of metal specimens with different electrical conditions to form an oxide film on the device was developed. Supply current variable was used for the PWM modulation, (+) and (-) polarity change of the H-bridge bipolar pulse voltage to supply the was that. As a result, a more uniform pores with unipolar film was formed.

• Korean Journal of Agricultural Science
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• v.27 no.2
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• pp.95-100
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• 2000

This study was carried out to estimate the effect of forest fire on physical and chemical properties of soil. The forest fire was in April 1997 in pinus densiflora dominant forest at Chungju of Chungbuk. After forest fire, dead trees were not cut. Soil samples were collected at 0-5, 5-10, and 10-20cm soil depths in November 1998 from the burned and unburned sites. The analyzed factors were soil organic matter, total N, available P, exchangeable K, Ca, and Mg, and CEC, pH, bulk density, and moisture content. There was no forest floor in burned site, but unburned site has the forest floor of 4cm thick. There were no differences in soil organic matter, total N, available P, exchangeable K, Ca, and Mg, and CEC, pH, bulk density, moisture content in all soil depth, between burned and unburned sites, except in available P in 5-10cm soil depth. Forest fire had not changed the physical and chemical soil properties in this study. However, burning of vegetation and forest floor organic matter may have adverse influence on long-term site productivity.