• Ceramist
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• v.22 no.4
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• pp.452-463
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• 2019

A quartz glass crucible is the essential material for manufacturing silicon ingots such as semiconductors and solar cells. Quartz glass crucibles for semiconductors and solar cells are made similar, but differ in surface purity, structure and durability. Recently, ultra high purity synthetic glass crucibles for semiconductors have become more important due to foreign problems. In Korea, it has succeeded in producing 28-inch quartz glass crucibles through the past 10 years. However, 32-inch synthetic quartz glass for the production of silicon ingots for semiconductors is not up to the level of advanced technology, and the technology gap is expected to be 2 to 3 years. In order to overcome these technological gaps and localize synthetic quartz glass ware, close cooperation between production companies and demand companies and localization of synthetic quartz glass powder must also be made. In addition, if government support can be added, faster results can be expected.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.3
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• pp.115-120
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• 2022

A brown ring (hereinafter referred to as BR) on the inner surface of a quartz glass crucible used in the manufacturing process of a silicon ingot for semiconductor wafers was studied. BR is 20~30 ㎛ in size and has an asymmetric brown ring shape. The size and distribution of BR were different depending on the crucible location, and the size and distribution of BR were the largest and most abundant in the round part with the highest crucible temperature during Si ingot growth. BR contains cristobalite, which has a higher coefficient of thermal expansion than quartz glass, so it is considered that surface cracks appear. The color development of BR and pin holes are presumed to be due to oxygen vacancies.

• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.50-52
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• 2022

Brownish rings (BRs) with white interiors are formed during the manufacture of silicon ingots in quartz glass crucibles. These BRs inhibit the yield of silicon ingots. However, the composition and mechanism of the formation of these BRs remain unclear thus far. Therefore, in this study, we analyzed the color and shape of these BRs. Raman analysis revealed that the brown and white colors appear owing to oxygen deficiency rather than crystallization from excess oxygen supply as previously assumed. Moreover, the dark shade of the brown areas depends on the degree of oxygen deficiency and the asymmetrical width of the brown areas is attributed to the direction of the molten silicon flow, which is influenced by the rotation and heat of the ingot crucible.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.3
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• pp.99-105
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• 2018

In order to avoid un-uniform crystallization on the surface of a quartz glass crucible that is known to affect the production yield of the single crystal silicon, Ba (barium) was selected as a crystallization promotor and the inner surface of the crucible was coated using Ba (barium hydroxide octahydrate)-solution by the spray pyrolysis method. For un-coated crucible, it was found that the crystallization of its surface started at $1350^{\circ}C$, and at $1450^{\circ}C$ the surface was uniformly crystallized with ${\beta}$-cristobalite phase. It was found that the crucible coated with Ba began to be crystallized from $1000^{\circ}C$ and was uniformly crystallized on the crucible surface at $1300^{\circ}C$. In this case, ${\alpha}$-cristobalite and needle-shaped $BaSi_2O_5$ phase were created and disappeared as a crystal phase, and the ${\beta}$-cristobalite phase was eventually evenly distributed over the Ba-coated crucible surface.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.705-710
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• 2001

So for the quartz-glassy crucible wastes which was used for pulling up silicon-single-crystal ingot have simply reused for refractory raw-materials, or exhausted. This study is concerned on the advanced recycling-technology that is obtained by the proper micro-particle preparation process in order to fabricate fine amorphous silica filler for EMC (Epoxy Molding Compound). Therefore, this paper will deal with the physical, chemical and thermal pre-treatment process for efficient impurity removal and with the proper micro-particle process for producing the amorphous silicafiller. In view of the results, if the chemical, physical and thermal pre-treatment process for efficient elimination of impurity was passed, the purity of wasted fused glassy crucible is almost equal to the its of first anhydrous quartz glass. Thus, it was understood that this wasted fused glassy crucible was sufficient value of recycling, though it was damaged. When the ingot was fabricated, Phase transformation of crystallization by heat treatment (heat hysteresis phenomenon) was not changed. So, it was understood that as fused silica in the amorphous state, as It is, recycling possibility was very high

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1999.06a
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• pp.419-431
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• 1999

InP, III-V binary compound semiconductor, single crystal was grown by VGF (vertical gradient freeze) method using quartz ampoule and its electrical optical properties were investigated. Phosphorous powders were put in the bottom of quartz ampoule and Indium metal changed in conical quartz crucible hat was attached at the upper side position inside the quartz ampoule. It was vacuous under the pressure of 10-5 Torr and sealed up. In metal in the quartz crucible was melted at 1070$^{\circ}C$ and phophorous sublimated at 450$^{\circ}C$, there after it was diffused in In melt and so InP composition was formed. By cooling the InP composition melt (2$^{\circ}C$∼5$^{\circ}C$/hr of cooling rate) in range of 1070$^{\circ}C$∼900$^{\circ}C$, InP crystal was grown. the grown InP single crystals were investigated by X-ray analysis and polarized optical microscopy. Electrical properties of them were measured by Van der Pauw method. At the cooling rate of 2$^{\circ}C$/hr, its direction was (111), quality of the ingot ws better upper side of the ingot than lower. It was found that the InP crystals were n-type semiconductor and the carrier concentration, electron mobility and relative resistivity were 1015∼1016/㎤, 2x103∼3x104$\textrm{cm}^2$/Vsec and 2x10-1∼2x10-3Ωcm in the range of 150K∼300K, respectively.

• Journal of the Korean Ceramic Society
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• v.17 no.4
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• pp.203-207
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• 1980

The optical absorption of high index glasses of the system TiO2-BaO-B2O3 prepared from the raw materials for an optical waveguide glass has been measured in the near ultraviolet region. The amount of Ti3+ in the glass could be reduced to a level less than 5 ppm by melting a batch added with pure nitric acid, using a fused quartz crucible in an oxygen gas atmosphere. The ultra-pure glass of 10mm thick prepared in such a way did not show any appreciable color even for the one containing 30 mol% TiO2 and having refractive index nD of 1.84 and Abbe's number vD of 28.8. The wavelength of ultraviolet absorptin edge was longer for the glass of higher index and higher dispersdion. The melting of a TiO2 containing glass in a platinum crucible resulted in a coloration of the glass due to the dissolved plutinum from the crucible, which was more intense for the one containing larger amount of TiO2.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.4
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• pp.128-135
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• 2022

The inside of a quartz glass crucible for semiconductor processing, called a transparent layer, is manufactured using synthetic silica powder. Bubbles existing in the transparent layer of the crucible cause a problem of reducing the quality of the crucible as well as the yield of the silicon ingot. Therefore, the main goal of the synthetic silica powder, which is the raw material of the transparent layer, is to minimize the bubble generation factor. For this purpose, in the case of synthetic silica powder, it is necessary to minimize silanol groups, carbon and pores. In this study, synthetic silica gel was prepared using the sol-gel method, and changes in carbon content and specific surface area were investigated according to calcination temperature and dwelled time in a two-stage calcination process. The first-stage calcination process was performed between 500℃ and 600℃ and the second-stage calcination process was performed between 1000℃ and 1100℃. The dwelled time was carried out from 10 minutes to a maximum of 12 hours. The carbon content of the powder calcined at 1000℃ for 1 hour was 0.0031 wt.%, and the specific surface area of the powder calcined at 1100℃ for 12 hours was 16.6 m²/g.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.1
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• pp.33-41
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• 1994

It is well known that the position and the shape of the S/L interface affect the qualities of the single crystal in the growth process. Thus the information of the temperature profile in the growth system is very important. In this study, we developed the program to predict the temperature profile from the setting values of the heating blocks in VGF(vertical gradient freezing) single crystal growth system. With this program, we studied the effects of the materials and the sizes of support rod, the materials of the crucible on the S/L interface shape. The larger radius and/or smaller thermal diffusivity support rod was, the flatter the S/L interface was. When the thermal conductivity of crucible was isotropic, the S/L interface was more concave downward to the solid phase in proportional to the increase of thermal diffusivity of the crucible. By the comparison of the S/L interface shape between PBN crucible and quartz crucible for the same condition, the effect of anisotropy of thermal conductivity of crucible showed different trends with respect to the position of the S/L interface.

• Composites Research
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• v.19 no.6
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• pp.32-37
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• 2006

This paper summarizes the processing inorganic continuous fibers from Korean minerals. Continuous filament fibers have been produced from two rocks, basalt and quartz diorite porphyry(QDP), by melting method. The essence of the method is that the vitrified materials was placed into the bushing, platinum/rhodium alloy crucible with a nozzle, and heated electrically to a temperature which allowed fiber spinning. Vitrified basalt without additive was suitable for producing continuous filament fiber. However doping quartz diorite porphyry with boric oxide yielded a material which could be pulled continuously.