• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.263-264
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• 2008

• Journal of the Microelectronics and Packaging Society
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• v.9 no.4
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• pp.17-23
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• 2002

The more productive and stable fabrication can be obtained by applying chemical mechanical polishing (CMP) process to shallow trench isolation (STI) structure in 0.18 $\mu\textrm{m}$ semiconductor device. However, STI-CMP process became more complex, and some kinds of defect such as nitride residue, tern oxide defect were seriously increased. Defects like nitride residue and silicon damage after STI-CMP process were discussed to accomplish its optimum process condition. In this paper, we studied how to reduce torn oxide defects and nitride residue after STI-CMP process. To understand its optimum process condition, We studied overall STI-related processes including trench depth, STI-fill thickness and post-CMP thickness. As an experimental result showed that as the STI-fill thickness becomes thinner, and trench depth gets deeper, more tern oxide were found in the CMP process. Also, we could conclude that low trench depth whereas high CMP thickness can cause nitride residue, and high trench depth and over-polishing can cause silicon damage.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.389-396
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• 2017

Restorations of automotive parts have been done ever since the first vehicle was produced. Because the most expensive parts of a vehicle are in the engine system, there have been various restoration methods developed for engine parts. In the case of commercial diesel engines, the fuel injection device is a key and expensive component. It also has a significant effect on vehicle performance. In particular, reduced engine power and increased exhaust gas emissions may result from mechanical damage due to abrasion of the spill valve in the fuel injection system of a diesel engine. In this paper, restoration techniques for damaged parts are applied to restore the abrasion of a spill valve of fuel injection, also called as the "unit injector", of commercial diesel engines. In order to recover the damage, optimized polishing techniques using hard-metal and coating processes are applied. To evaluate restoration techniques for the spill valve, performance and durability tests are performed on a test bench.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.3
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• pp.116-121
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• 2006

Most high-k materials are well known not to be etched easily, Some problems such as low etch rate poor sidewall angle, plasma damage, and process complexity were emerged from the high-density DRAM fabrication. Chemical mechanical polishing (CMP) by a damascene process was proposed to pattern this high-k material was polished with some commercial silica slurry as a function of pH variation. Sufficient removal rate with adequate selectivity to realize the pattern mask of tera-ethyl ortho-silicate (TEOS) film for the vertical sidewall angle were obtained. The changes of X-ray diffraction pattern and dielectric constant by CMP process were negligible. The planarization was also achieved for the subsequent multi-level processes. Our new CMP approach will provide a guideline for effective patterning of high-k material by CMP technique.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.189-192
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• 2001

Recently, STI process is getting attention as a necessary technology for making high density of semiconductor by devices isolation method. However, it does have various problems caused by CMP nprocess, such as torn oxide defects, nitride residues on oxide, damages of si active region, contaminations due to post-CMP cleaning, difficulty of accurate end point detection in CMP process, etc. In this work, the various defects induced by CMP process was introduced and the above mentioned problems of CMP process was examined in detail. Finally, the guideline of future CMP process was presented to reduce the effects of these defects.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.189-192
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• 2001

Recently, STI process is getting attention as a necessary technology for making high density of semiconductor by devices isolation method. However, it does have various problems caused by CMP process, such as torn oxide defects, nitride residues on oxide, damages of si active region, contaminations due to post-CMP cleaning, difficulty of accurate end point detection in CMP process, etc. In this work, the various defects induced by CMP process was introduced and the above mentioned Problems of CMP process was examined in detail. Finally, the guideline of future CMP process was presented to reduce the effects of these defects.

• The Journal of Advanced Prosthodontics
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• v.10 no.4
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• pp.315-320
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• 2018

PURPOSE. Fractures, occlusal adjustments, or marginal corrections after removing excess composite cements result in rough surfaces of all-ceramic FPDs. These have to be polished to prevent damage of the surrounding tissues. The aim of this study was to evaluate the roughness of zirconia, silicate-ceramic, and composite after polish with different systems for intraoral use. MATERIALS AND METHODS. Each set of 50 plates was made of zirconia, silicate-ceramic, and composite. All plates were ground automatically and were divided into 15 groups according to the treatment. Groups Zgrit, Sgrit, and Cgrit received no further treatment. Groups Zlab and Slab received glaze-baking, and group Clab was polished with a polishing device. In the experimental groups Zv, Sv, Cv, Zk, Sk, Ck, Zb, Sb, and Cb, the specimens were polished with ceramic-polishing systems "v", "k", and "b" for intraoral use. Roughness was measured using profilometry. Statistical analysis was performed with ANOVA and $Scheff{\acute{e}}$-procedure with the level of significance set at P=.05. RESULTS. All systems reduced the roughness of zirconia, but the differences from the controls Zgrit and Zlab were not statistically significant (P>.907). Roughness of silicate ceramic was reduced only in group Sv, but it did not differ significantly from both controls (P>.580). Groups Cv, Ck, and Cb had a significantly rougher surface than that of group Clab (P<.003). CONCLUSION. Ceramic materials can be polished with the tested systems. Polishing of interface areas between ceramic and composite material should be performed with polishing systems for zirconia first, followed by systems for veneering materials and for composite materials.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.365-376
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• 1999

The importance of finishing and polishing the restoration has been described by several authors. The final step provides for improved metallurgical properties, better marginal adaptation, reduced plaque accumulation. Unfortunately, finishing of the restorations can produce damage from temperature rises at the pulpal wall. The aim of this study was to determine the changes in temperature can be occurred during the use of finishing and polishing instruments under a variety of conditions. ; with or without a water coolant, intermittent or continuous operation, high or low rotation speed, remaining dentin thickness and various restorative materials. Class V preparations were cut on extracted molars and restored with composite resin(Z 100), resin-modified glass ionomer cements(Dyract, Fuji II LC), and amalgam. Finishing was done with aluminum oxide coated disc($Sof-lex^{(R)}$ polishing disc, 3M, USA). The following results were obtained. 1. The rise of temperature during polishing of amalgam restorations was the highest among the all experimental groups except polishing with water coolant(P<0.05). However, there were no statistical differences in temperature rises between Z 100, Dyract and Fuji II LC(P>0.05). 2. The intrapulpal temperature was greatly influenced by the applied time, and intermittent polishing was showed significantly lower temperature rises than continuous polishing(P<0.01). 3. The intrapulpal temperature was increased according to the application of polishing regard less of using water coolant. However, polishing with water coolant showed significantly lower temperature in the pulp than not used water coolant(P<0.01).

• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.613-622
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• 1996

The purposes of this study were to evaluate and compare the frequency of ceramic bracket fracture, frequency of enamel fracture, bond fracture site, adhesive remnant index after mechanical and electrothermal debracketing, to evaluate effectiveness of high and low speed rotary instrument and ultrasonic instrument during residual adhesive remnants removal, and to measure resin film surface(percentage) using by image analyser(Leco 300). Bond fracture site, bracket fracture, and enamel surface damage were examined by scanning electron microscope. The following results were obained : 1. In the mechanical debracketing group, the bond failed predominantly at enamel-adhesive interface with the bulk of adhesive remaining on bracket base. 2. In the eletrothermal debracketing group, the bond failed predominantly at adhesive-bracket interface with the bulk of adhesive remaining on enamel surface. 3. The most effectiveness of residual resin removal was obtained by means of the resin polishing bur and the order of scratch formation was the procedure using tungsten carbide bur, ultrasonic scaler, sof-lex disc, and polishing bur. 4. The order of the resin film surface percentage was ultrasonic scaler, tungsten carbide bur, sof-lex disc, and resin polishing bur.

• Corrosion Science and Technology
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• v.22 no.3
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• pp.164-174
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• 2023

Electropolishing technology uses an electrochemical reaction and improves surface roughness, glossiness, and corrosion resistance. In this investigation, electropolishing was performed to improve the corrosion resistance of super austenitic stainless steel. As a result of electropolishing, surface roughness (0.16 ㎛) was improved by about 76.5% compared to mechanical polishing (0.68 ㎛). In addition, the electropolished surface was smooth because the average and variance values of the depth histogram were small. Tafel analysis was performed after a potentiodynamic polarization experiment with seawater temperature, and the microstructure was compared and analyzed. The corrosion current density at 30 ℃, 60 ℃, and 90 ℃ was reduced by 0.083 ㎂/cm², 0.296 ㎂/cm², and 0.341 ㎂/cm², respectively. Pitting occurred in the mechanical polished specimen at 30 ℃, but partial intergranular corrosion was observed in the electropolished specimen, and pitting occurred predominantly at both 60 ℃ and 90 ℃. In addition, the damage depths of the electropolished specimen were shallower than those of mechanical polishing at 30 ℃ and 60 ℃, but the opposite result was seen at 90 ℃.