• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.1
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• pp.23-27
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• 2005

We observed that optical properties of silicon changed under high dose electron irradiation at 250 keV. Our experimental results revealed that the optical transmission through a silicon wafer is significantly increased by electron irradiation. Transmission increase by the change in the absorption coefficient is explained through an analogy with amorphous silicon. Moreover, solar cell open-circuit voltages indicated that defects were generated by electron irradiation, and that the defects responded to annealing. Our results demonstrated that the optical properties of silicon can be controlled by a combination of electron irradiation and hydrogen annealing.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.3
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• pp.89-95
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• 2001

The CZ-silicon crystal was annealed at $1350^{\circ}C$ to dissolve the vacancy type grown-in defects. A this temperature, the equilibrium concentration of the oxygen in the silicon crystal is around $1.7{\times}10^{18}$ which induces the oxygen undersaturation in the silicon crystal. This situation results in the faster dissolution of the grown-in defects in the bulk of the silicon wafer than near the surface. This indicates the possibility that the presence of the higher concentration of silicon interstitial hinders the dissolution of the grown-in defects, which were known to compose of the vacancy clusters with surrounding silicon oxide film. This expectation was confirmed by the observation that the slower dissolution of the grown-in defects near the surface of the silicon wafer in the oxygen atmosphere than in the argon atmosphere. This result is quite opposite to the previous argument hat presence of the excess silicon interstitial leads to faster dissolution of the vacancy type defects.

• Journal of the Korean institute of surface engineering
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• v.31 no.5
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• pp.237-244
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• 1998

In this stydy, submicron shallow trenches applied to STI(shallow tench isolation) were etched using inductively coupled $CI_2$/HBr and $CI_2/N_2$plasmas and the physical and electrical defects remaining on the etched silicon trench surfaces and the effects of various annealing and oxidation on the removal of the defects were studied. Using high resolution electron microscopy(HRTEM), Physical defects were investigated on the silicon trench surfaces etched in both 90%$CI_2$/ 10%$N_2$ and 50%$CI_2$/50%HBr. Among the areas in the tench such as trench bottom, bottom edge, and sidewall, the most dense defects were found near the trench bottom edge, and the least dense defects were found near the trench bottom edge, and least dense defects compared to that etched with ment as well as hydrogen permeation. Thermal oxidation of 200$\AA$ atthe temperature up to $1100^{\circ}C$apprars not to remove the defects formed on the etched silicon trenches for both of the etch conditions. To remove the physicall defects, an annealing treatment at the temperature high than $1000^{\circ}C$ in N for30minutes was required. Electrical defects measured using a capacitance-voltage technique showed the reduction of the defects with increasing annealing temperature, and the trends were similar to the results on the physical defects obtained using transmission electron microscopy.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.2
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• pp.45-50
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• 2005

During oxidation process, several type of defects are formed on the surface of the silicon crystal which was damaged mechanically before oxidation. As the size of abrasive particle increases multiple dislocation loops are produced favorably over oxidation-induced stacking faults, which are dominantly produced when ground with finer abrasive particle. These defects are not related with the crystal growth process like Czochralski or directional solidification. During directional solidification process, twins and stacking faults are the two major defects observed in the bulk of the silicon crystal. On the other hand, slip dislocations produced by the thermal stress are not observed. Thus, not only in single crystalline silicon crystal but also in multi-crystalline silicon, extrinsic gettering process with programmed production of surface defects might be highly applicable to silicon wafers for purification.

• Applied Science and Convergence Technology
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• v.23 no.3
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• pp.113-127
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• 2014

For more than five decades, silicon has dominated the semiconductor industry that supports memory devices, ICs, photovoltaic devices, etc. Photoluminescence (PL) is an attractive silicon characterization technique because it is contactless and provides information on bulk impurities, defects, surface states, optical properties, and doping concentration. It can provide high resolution spectra, generally with the sample at low temperature and room-temperature spectra. The photoluminescence properties of silicon at low temperature are reviewed and discussed in this study. In this paper, silicon bulk PL spectra are shown in multiple peak positions at low temperature. They correspond with various impurities such as In, Al, and Be, phonon interactions, for example, acoustical phonons and optical phonons, different exciton binding energies for boron and phosphorus, dislocation related PL emission peak lines, and oxygen related thermal donor PL emissions.

• The Journal of the Korean dental association
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• v.47 no.9
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• pp.596-606
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• 2009

Aim : The ultimate goal of periodontal treatment is regeneration of periodontium that have been lost due to inflammatory periodontal disease. Recently, Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate bone substitute have been introduced to achieve periodontal regeneration. The purpose of this study is to evaluate the effect of the Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate(BoneMedik-$DM^{(R)}$, Meta Biomed Co., Ltd. Oksan, Korea) on periodontal intrabony defects. Methods and materials : Clinical effects of Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate implantation in intrabony defects were evaluated 6 months after surgery in Sixty-one intrabony defects from Fourty-six patients with chronic periodontitis. Twenty-nine experimental defects in twenty-five patients received the Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate(test group), while Thirty-Three defects in twenty-one patients were treated with flap procedure only( control group). Comparative observation were done for preoperative and postoperative differences between control and experimental clinical parameters,-clinical attachment 10ss(CAL), probing depth(PD), bone probing depth(BPD), gingi val recession. Results : Postoperative improvements in CAL, PD, BPD were observed in both test and control groups(P<0.0l). However, the improvements in CAL, PD, BPD of the test group were significantly greater than control group. Conclusion : Healing of the both groups were uneventful during experimental periods. Use of Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate in a flap operation resulted in significantly greater improvements in CAL, PD, and BPD over flap operation alone. Silicon contained Coralline Hydroxyapatite and Beta Tricalcium Phosphate will be good bone substitute materials for treatment of intrabony defects.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.5
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• pp.606-613
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• 2011

In this paper, patterns of laser scattering and detection of micro defects have been investigated based on Rayleigh criterion for silicon wafer in solar cell. Also, a new laser scattering mechanism is designed using characteristics of light scattering against silicon wafer surfaces. Its parameters are to be optimally selected to obtain effective and featured patterns of laser scattering. The optimal parametric ranges of laser scattering are determined using the mean intensity of laser scattering. Scattering patterns of micro defects are investigated at the extracted parameter region. Among a lot of pattern features, both maximum connected area and number of connected component in patterns of laser scattering are regarded as the important information for detecting micro defects. Their usefulness is verified in the experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1083-1086
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• 2005

Light scattering measurement system that can evaluate light scattering characteristic from defects on silicon wafer surface has been developed. The system uses $Ar^+$ laser as an illumination source, and a highly sensitive photomultiplier tube (PMT) for detecting scattered light from defects. Unlike with conventional measurement system, our system has ability to measure scattered light pattern from wide range of scattering angles with changeable incidence condition. It is shown that our developed system is effective to discriminate the types and sizes of defects from basic experimental results using a microscatch and a PSL sphere.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.335-338
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• 1998

We have calculated ultra-low energy silicon-self ion implantations and silicon damages through classical molecular dynamics simulation using empirical potentials. We tested whether the recently developed environment-dependent interatomic ptential (EDIP) was suitable for ultra low ion implantation simulation, and found that point defects formation energies were in good agrrement with other theoretical calculations, but the calculated vacancy migration energy was overestimated. The number of isolated defects that are produced by collision cascades are onlya few of the total number of defects, and fmost of the damages are concentrated into amorphous-like pockets.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.185-186
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• 2005

Intrinsic gettering is usually used to improve wafer quality which is an important factor for reliable ULSI devices. The two-step annealing method was adopted in order to investigate interactions between oxygens and secondary defects during oxygen precipitation process in lightly and heavily boron doped silicon wafers with high energy $^{11}B^+$ ion implantation. Secondary defects were inspected nearby the projected range by high resolution transmission electron microscopy. Oxygen pileup was measured in the vicinity of the projected range by secondary ion mass spectrometry for heavily boron doped silicon wafers.