• 한국세라믹학회지
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• 제31권5호
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• pp.485-490
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• 1994

The reactive ion etching characteristics of aluminum oxide films, prepared by PECVD, were investigated in the CCl4 plasma. The atomic chlorine concentration and the DC self bias were determined at various etching conditions, and their effects on the etch rate of aluminum oxide film were studied. The bombarding energy of incident particles was found to play the more important role in determining the etch rate of aluminum oxide rather than the atomic chlorine concentration. It is considered to be because the bombardment of ions or neutral atoms breaks the strong Al-O bonds of aluminum oxide to help activate the formation reaction of AlCl3 which is the volatile etch product.

• Restorative Dentistry and Endodontics
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• 제41권2호
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• pp.83-90
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• 2016

Objectives: This study was evaluated the marginal microleakage of two different adhesive systems before and after aging with two different dye penetration techniques. Materials and Methods: Class V cavities were prepared on the buccal and lingual surfaces of 48 human molars. Clearfil SE Bond and Single Bond (self-etching and etchand-rinse systems, respectively) were applied, each to half of the prepared cavities, which were restored with composite resin. Half of the specimens in each group underwent 10,000 cycles of thermocycling. Microleakage was evaluated using two dimensional (2D) and three dimensional (3D) dye penetration techniques separately for each half of each specimen. Data were analyzed with SPSS 11.5 (SPSS Inc.), using the Kruskal-Wallis and Mann-Whitney U tests (${\alpha}=0.05$). Results: The difference between the 2D and 3D microleakage evaluation techniques was significant at the occlusal margins of Single bond groups (p = 0.002). The differences between 2D and 3D microleakage evaluation techniques were significant at both the occlusal and cervical margins of Clearfil SE Bond groups (p = 0.017 and p = 0.002, respectively). The difference between the 2D and 3D techniques was significant at the occlusal margins of non-aged groups (p = 0.003). The difference between these two techniques was significant at the occlusal margins of the aged groups (p = 0.001). The Mann-Whitney test showed significant differences between the two techniques only at the occlusal margins in all specimens. Conclusions: Under the limitations of the present study, it can be concluded that the 3D technique has the capacity to detect occlusal microleakage more precisely than the 2D technique.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.6.1-6.1
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• 2011

Nanoscale block copolymer (BCP) patterns have been pursued for applications in sub-30 nm nanolithography. BCP self-assembly processing is scalable and low cost, and is well-suited for integration with existing semiconductor fabrication techniques. However, one of the major technical challenges for BCP self-assembly is limited tunability in pattern geometry, dimension, and functionality. We suggest methods for extending the degree of tunability by choosing highly incompatible polymer blocks and utilizing solvent vapor treatment techniques. Siloxane BCPs have been developed as self-assembling resists due to many advantages such as high etch-selectivity, good etch-resistance, long-range ordering, and reduced line-edge roughness. The large incompatibility leads to extensive degree of pattern tunability since the effective volume fraction can be easily manipulated by solvent-based treatment techniques. Thus, control of the microdomain size, periodicity, and morphology is possible by changing the vapor pressure and the mixing ratio of selective solvents. This allows a range of different pattern geometry such as dots, lines and holes and critical dimension simply by changing the processing conditions of a given block copolymer without changing a polymer chain length. We demonstrate highly extensive tunability (critical dimension ~6~30 nm) of self-assembled patterns prepared by a siloxane BCP with extreme incompatibility.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.285-285
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• 2011

EUVL (Extreme Ultra Violet Lithography) is one of competitive lithographic technologies for sub-30nm fabrication of nano-scale Si devices that can possibly replace the conventional photolithography used to make today's microcircuits. Among the core EUVL technologies, mask fabrication is of considerable importance since the use of new reflective optics having a completely different configuration compared to those of conventional photolithography. Therefore new materials and new mask fabrication process are required for high performance EUVL mask fabrication. This study investigated the etching properties of SnO2 (Tin Oxide) as a new absorber material for EUVL binary mask. The EUVL mask structure used for etching is SnO2 (absorber layer) / Ru (capping / etch stop layer) / Mo-Si multilayer (reflective layer) / Si (substrate). Since the Ru etch stop layer should not be etched, infinitely high selectivity of SnO2 layer to Ru ESL is required. To obtain infinitely high etch selectivity and very low LER (line edge roughness) values, etch parameters of gas flow ratio, top electrode power, dc self - bias voltage (Vdc), and etch time were varied in inductively coupled Cl2/Ar plasmas. For certain process window, infinitely high etch selectivity of SnO2 to Ru ESL could be obtained by optimizing the process parameters. Etch characteristics were measured by on scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses. Detailed mechanisms for ultra-high etch selectivity will be discussed.

• Restorative Dentistry and Endodontics
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• 제36권5호
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• pp.385-396
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• 2011

연구목적: 본 연구는 치근벽의 전처리 개념과 접착제의 중합방법이 레진계 근관충전제의 치근단 밀폐능에 미치는 영향을 평가하였다. 연구 재료 및 방법: 3가지 다른 접착변수를 조합하여 충전한 Resilon-RealSeal 시스템의 근단미세누출을 색소침투법을 이용하여 통상의 가타퍼쳐 충전과 비교하였다. 실험군은 자가부식형 RealSeal primer와 이중중합형 RealSeal sealer를 이용하여 Resilon 충전한 SEDC군, 산부식없이 Scotchbond Multi-Purpose primer를 적용한 후 접착제는 광중합하고 Resilon을 충전한 NELC군, 및 Scotchbond Multi-Purpose의 접착강화제와 접착제를 total etch/wet bonding과 광중합의 술식을 정확하게 지켜서 Resilon을 충전한 TELC군으로 구분하였다. 대조군(GPCS)에서는 통상의 AH26 plus sealer를 사용하여 가타퍼쳐를 충전 하였다. 결과: 치아장축방향의 색소침투는 TELC군에서 GPCS군과 SEDC군에 비해 유의하게 작았다(Kruskal-Wallis test, p < 0.05). 횡단면의 미세누출 점수도 TELC군이 근첨으로부터 2 - 5 mm의 범위에서 다른 군에 비해 유의하게 낮았다(Kruskal-Wallis test, p < 0.05). 결론: 레진계 근관충전제를 사용 시에는, 자가부식형 전처리제와 이중중합형 sealer보다는, total etch/wet bonding 개념과 적절한 광중합을 도모하는 전처리제 및 접착제의 사용이 치근단 미세누출을 감소시키므로 추천된다.

• 대한치과기공학회지
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• 제38권3호
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• pp.193-199
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• 2016

Purpose: The purpose of this study was to know of photopolymerization effect of self-etch dual-cured resin cement on different transmittance and thickness of zirconia disks. Methods: The two types of transparent and opaque zirconia speciments were prepared. The five speciments of each groups were seperated with 0.5mm and 1.0mm thickness. Degree of conversion(DC) were studied by FT-IR spectroscopy using ATR method before and after irradidaion for 40 sec. Results: The relative DC was showed the higher results of ZS5 as compared with ZS10 (p < 0.05). And OP5 and OP10 were lower results than ZS10 (p < 0.05). Conclusion: The photopolymerization effect of dual-cured resin cement were affected by the transmittance and thickness of zirconia.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권5호
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• pp.309-314
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• 1999

The magnetized helical resonator plasma etcher has been built. Electron density and temperature were measured as functions of rf source power, axial magnetic field, and pressure. The results show electron density increases as the magnetic field increases and reached $2\times1012cm^{-3}$,/TEX>. The oxide etch rate and selectivity to polysilicon were investigated as the above mentioned conditions and self-bias voltage. We can obtain the much improved oxide etch selectivity to polysilicon (60 : 1) by applying the external axial weak magnetic field in magnetized helical resonator plasma etcher.

• Restorative Dentistry and Endodontics
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• 제48권2호
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• pp.14.1-14.11
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• 2023

Objectives: This study investigated the effect of an aluminum chloride hemostatic agent on the shear bond strength (SBS) of a universal adhesive to dentin. Materials and Methods: Eighty extracted human molars were trimmed at the occlusal dentin surfaces and divided mesiodistally. According to hemostatic agent application, specimens were randomly allocated into control (C) and hemostatic agent (Traxodent; H) groups. Each group was divided into 4 subgroups according to the adhesive system (n = 20): Scotchbond Multi-Purpose (SBER), Clearfil SE Bond (CLSE), All-Bond Universal etch-and-rinse mode (ALER), and All-Bond Universal self-etch mode (ALSE). SBS was measured for half of the specimens at 24 hours, and the other half were thermocycled in water baths (group T). Fracture surfaces were examined to determine the failure mode. The SBS was measured, and data were analyzed using 1-way analysis of variance, the Student's t-test, and the Tukey honestly significant difference test (p = 0.05). Results: No significant differences in SBS were found between groups C and H for any adhesive system at 24 hours. After thermocycling, a statistically significant difference was observed between CT+ALSE and HT+ALSE (p < 0.05). When All-Bond Universal was applied to hemostatic agent-contaminated dentin, the SBS of H+ALSE was significantly lower than that of H+ALER (p < 0.05). The SBER subgroups showed no significant differences in SBS regardless of treatment and thermocycling. Conclusions: When exposed dentin was contaminated by an aluminum chloride hemostatic agent before dentin adhesive treatment, application of All-Bond Universal in etch-and-rinse mode was superior to self-etch mode.

• Restorative Dentistry and Endodontics
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• 제40권4호
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• pp.299-305
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• 2015

Objectives: The purpose of this study was to investigate the effectiveness of multiple decontamination procedures for salivary contamination after curing of a universal adhesive on dentin bond strength according to its etch modes. Materials and Methods: Forty-two extracted bovine incisors were trimmed by exposing the labial dentin surfaces and embedded in cylindrical molds. A universal adhesive (All-Bond Universal, Bisco) was used. The teeth were randomly divided into groups according to etch mode and decontamination procedure. The adhesive was applied according to the manufacturer's instructions for a given etch mode. With the exception of the control groups, the cured adhesive was contaminated with saliva for 20 sec. In the self-etch group, the teeth were divided into three groups: control, decontamination with rinsing and drying, and decontamination with rinsing, drying, and adhesive. In the etch-and-rinse group, the teeth were divided into four groups: control, decontamination with rinsing and drying, decontamination with rinsing, drying, and adhesive, and decontamination with rinsing, drying, re-etching, and reapplication of adhesive. A composite resin (Filtek Z350XT, 3M ESPE) was used for filling and was cured on the treated surfaces. Shear bond strength was measured, and failure modes were evaluated. The data were subjected to one-way analysis of variation and Tukey's HSD test. Results: The etch-and-rinse subgroup that was decontaminated by rinse, drying, re-etching, and reapplication of adhesive showed a significantly higher bond strength. Conclusions: When salivary contamination occurs after curing of the universal adhesive, additional etching improves the bond strength to dentin.

• Restorative Dentistry and Endodontics
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• 제42권3호
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• pp.168-175
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• 2017

Objectives: This double-blind randomized placebo-controlled clinical trial evaluated the ability of a desensitizing agent and a self-etch adhesive on cervical dentin sensitivity (CDS) after periodontal surgery. Materials and Methods: Ninety hypersensitive teeth of 13 subjects were included in the study. After periodontal surgery, the teeth of each posterior sextant treated with one of the following materials: G1: Clearfil $S^3$ Bond (Kuraray Dental), G2: Gluma Desensitizer (Heraeus Kulzer), and G3: placebo (water). The sensitivity was assessed using evaporative stimuli before treatment (baseline, T0), 1 day after treatment (T1), after 1 week (T2), and 1 month (T3) according to visual analog scale (VAS). Results: Following the treatment, all the 3 groups showed significant reduction of CDS in T1 compared to T0. Reduction of CDS between T1 and T2 was observed only in G1 but there was no significant difference between T2 and T3 in this group. Although we observed a significant difference in T3 compared to T1 and T2 in G2 and G3, comparison of treatment groups in each assessment time showed a significant difference only in T3. According to paired comparison, this was due to the difference between G2 and G3. Conclusions: Dentin sensitivity following periodontal surgery will decrease spontaneously over time, but treating the sensitive teeth with Gluma Desensitizer and Clearfil $S^3$ Bond can have some benefits.