• Title/Summary/Keyword: Self-etch

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Effect of $Ga^+$ Ion Beam Irradiation On the Wet Etching Characteristic of Self-Assembled Monolayer ($Ga^+$ 이온 빔 조사량에 따른 자기 조립 단분자막의 습식에칭 특성)

  • Noh Dong-Sun;Kim Dea-Eun
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.326-329
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    • 2005
  • As a flexible method to fabricate sub-micrometer patterns, Focused Ion Beam (FIB) instrument and Self-Assembled Monolayer (SAM) resist are introduced in this work. FIB instrument is known to be a very precise processing machine that is able to fabricate micro-scale structures or patterns, and SAM is known as a good etch resistance resist material. If SAM is applied as a resist in FIB processing fur fabricating nano-scale patterns, there will be much benefit. For instance, low energy ion beam is only needed for machining SAM material selectively, since ultra thin SAM is very sensitive to $Ga^+$ ion beam irradiation. Also, minimized beam spot radius (sub-tens nanometer) can be applied to FIB processing. With the ultimate goal of optimizing nano-scale pattern fabrication process, interaction between SAM coated specimen and $Ga^+$ ion dose during FIB processing was observed. From the experimental results, adequate ion dose for machining SAM material was identified.

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Shear Bond Strength and Microleakage of a New Self-etch Sealant Containing S-PRG filler (S-PRG 필러를 포함하는 치면열구전색제의 전단결합강도 및 미세누출)

  • An, Jinseon;Lee, Juhyun;Seo, Hyunwoo;Park, Howon
    • Journal of the korean academy of Pediatric Dentistry
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    • v.43 no.4
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    • pp.347-353
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    • 2016
  • The purpose of this study was to evaluate shear bond strength and microleakage of a new self-etch fissure sealant containing S-PRG filler (BeautiSealant). Fourty-five premolars were randomly divided into three groups: SEPBS group (Self-etching primer + BeautiSealant), AEBS group (Phosphoric acid etching + BeautiSealant), AECP group (Phosphoric acid etching + $Clinpro^{TM}$ sealant). For the shear bond strength test, microcylinders of fissure sealant were bonded to prepared buccal surfaces of teeth and shear bond strengths were measured by a universal testing machine. For the microleakage test, sealants were applicated on each occlusal fissure of teeth. All teeth surface were coated with finger nail varnish, with the exception of a 1.0 mm window around the sealant margins. The teeth were immersed in 2% methylene blue solution for 24 hours and then rinsed in water. The teeth were then embedded in resin and cut buccolingually along the tooth axis and observed with a stereomicroscope to determine the degree of microleakage. SEPBS group demonstrated lower bond strength in comparison with that of AEBS and AECP groups (p < 0.05). However, no significant differences were observed between AEBS and AECP groups. There was no statistically significant difference in degree of microleakage among three groups.

EFFECT OF CUTTING INSTRUMENTS ON THE DENTIN BOND STRENGTH OF A SELF-ETCH ADHESIVE (상아질 삭제기구가 자가부식 접착제의 결합강도에 미치는 효과)

  • Lee, Young-Gon;Moon, So-Ra;Cho, Young-Gon
    • Restorative Dentistry and Endodontics
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    • v.35 no.1
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    • pp.13-19
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    • 2010
  • The purpose of this study was to compare the microshear bond strength of a self-etching primer adhesive to dentin prepared with different diamond points, carbide burs and SiC papers, and also to determine which SiC paper yield similar strength to that of dentinal surface prepared with points or burs. Fifty-six human molar were sectioned to expose the occlusal dentinal surfaces of crowns and slabs of 1.2 mm thick were made. Dentinal surfaces were removed with three diamond points, two carbide burs, and three SiC papers. They were divided into one of eight equal groups (n = 7); Group 1: standard diamond point(TF-12), Group 2: fine diamond point (TF-12F), Group 3: extrafine diamond point (TF-12EF), Group 4: plain-cut carbide bur (no. 245), Group 5: cross-cut carbide bur (no. 557), Group 6 : P 120-grade SiC paper, Group 7: P 220-grade SiC paper, Group 8: P 800-grade SiC paper. Clearfil SE Bond was applied on dentinal surface and Clearfil AP-X was placed on dentinal surface using Tygon tubes. After the bonded specimens were subjected to uSBS testing, the mean uSBS (n = 20 for each group) was statistically compared using one-way ANOV A and Tukey HSD test. In conclusion, the use of extrafine diamond point is recommended for improved bonding of Clearfil SE Bond to dentin. Also the use of P 220-grade SiC paper in vitro will be yield the results closer to dentinal surface prepared with fine diamond point or carbide burs in vivo.

Investigation of the residue formed on the silicon exposed to $C_4$F$_8$ helicon wave plasmas (고선택비 산화막 식각공정시 $C_4$F$_8$ 헬리콘 웨이브 플라즈마에 노출된 실리콘 표면의 잔류막 관찰)

  • 김현수;이원정;염근영
    • Journal of the Korean institute of surface engineering
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    • v.32 no.2
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    • pp.93-99
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    • 1999
  • Surface polymer layer formed on the silicon wafer during the oxide overetching using $C_4F_8$/ helicon wave plasmas and their characteristics were investigated using spectroscopic elipsometry, X-ray photoelectron spectroscopy, and secondary ion mass spectrometry. Overetch percentage and dc-self bias voltage were varied to investigate the effects on the characteristics of the polymers remaining on the overetched silicon surface. The increase of bias voltage from -80 volts to -120 volts increased the C/F ratio and carbon bondings such as C-C, $C-CF_x$/, and C-Si in the polymer while reducing the thickness of the polymer layer. However, the increase of the overetch percentage from 50% to 100% did not change the composition of the polymer layer and the carbon bondings in the polymer layer remained same even though it increased the polymer thickness. The polymer layer formed at the higher dc-self bias voltage was more difficult to be removed by the following various post-etch treatments compared to that formed at the longer overetch percentage.

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Recent Studies on Area Selective Atomic Layer Deposition of Elemental Metals (단일 원소 금속의 영역 선택적 원자층 증착법 연구 동향)

  • Min Gyoo Cho;Jae Hee Go;Byung Joon Choi
    • Journal of Powder Materials
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    • v.30 no.2
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    • pp.156-168
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    • 2023
  • The semiconductor industry faces physical limitations due to its top-down manufacturing processes. High cost of EUV equipment, time loss during tens or hundreds of photolithography steps, overlay, etch process errors, and contamination issues owing to photolithography still exist and may become more serious with the miniaturization of semiconductor devices. Therefore, a bottom-up approach is required to overcome these issues. The key technology that enables bottom-up semiconductor manufacturing is area-selective atomic layer deposition (ASALD). Here, various ASALD processes for elemental metals, such as Co, Cu, Ir, Ni, Pt, and Ru, are reviewed. Surface treatments using chemical species, such as self-assembled monolayers and small-molecule inhibitors, to control the hydrophilicity of the surface have been introduced. Finally, we discuss the future applications of metal ASALD processes.

Influence of silver nanoparticles on resin-dentin bond strength durability in a self-etch and an etch-and-rinse adhesive system

  • Jowkar, Zahra;Shafiei, Fereshteh;Asadmanesh, Elham;Koohpeima, Fatemeh
    • Restorative Dentistry and Endodontics
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    • v.44 no.2
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    • pp.13.1-13.9
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    • 2019
  • Objectives: This study evaluated the effect of dentin pretreatment with silver nanoparticles (SNPs) and chlorhexidine (CHX) on the microshear bond strength (${\mu}SBS$) durability of different adhesives to dentin. Materials and Methods: Occlusal surfaces of 120 human molars were ground to expose flat dentin surfaces. The specimens were randomly assigned to six groups (n = 20). Three groups (A, B, and C) were bonded with Adper Single Bond 2 (SB) and the other groups (D, E, and F) were bonded with Clearfil SE Bond (SEB). Dentin was pretreated with CHX in groups B and E, and with SNPs in groups C and F. The specimens were restored with Z250 composite. Half of the bonded surfaces in each group underwent ${\mu}SBS$ testing after 24 hours and the other half was tested after 6 months of water storage. Results: SNP application was associated with a higher ${\mu}SBS$ than was observed in the CHX and control groups for SEB after 24 hours (p < 0.05). A significantly lower ${\mu}SBS$ was observed when no dentin pretreatment was applied compared to dentin pretreatment with CHX and SNPs for SB after 24 hours (p < 0.05). The ${\mu}SBS$ values of the 6-month specimens were significantly lower than those obtained from the 24-hour specimens for all groups (p < 0.05). This decrease was much more pronounced when both adhesives were used without any dentin pretreatment (p < 0.05). Conclusions: SNPs and CHX reduced the degradation of resin-dentin bonds over a 6-month period for both adhesive systems.

EFFECT OF SALIVARY CONTAMINATION OF TEETH ON MICROTENSILE BOND STRENGTH OF VAR10US DENTIN BONDING SYSTEMS. (타액에 의한 오염이 상아질 접착제의 미세전단결합강도에 미치는 영향)

  • Choi, Kyoung-Kyu;Ryu, Gil-Joo
    • Restorative Dentistry and Endodontics
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    • v.28 no.3
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    • pp.203-208
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    • 2003
  • The purpose of this study was to evaluate the effect of salivary contamination of teeth on bonding efficacy of self-priming and self-etching DBSs. The materials used were Single Bond(SB, self-priming system, 3M), Unifil Bond(UB, self-etching system, GC), and Scotchbond Multi-Purpose Plus(SM, 3M) as control. Forty five human molars randomly allocated to three groups as dentin bonding systems tested and embedded in epoxy resin. Then the specimens were wet-ground to expose flat buccal enamel surface or flat occlusal dentin surface and cut bucco-lingually to form two halves with slow speed diamond saw. One of them was used under non-contamination, other under contamination with saliva. The bonding procedure was according to the manufacturer's directions and resin composite(Z-100, 3M Dental Products, St. Paul, MN) was built-up on the bonded surface 5mm high. The specimens were ground carefully at the enamel-composite interface with fine finishing round diamond bur to create an hour-glass shape yielding bonded surface areas of $1.5{\pm}0.1\textrm{mm}^2$. The specimens were bonded to the modified microtensile testing apparatus with cyanoacrylate, attached to the universal testing machine and stressed in tension at a CHS of 1mm/min. The tensile force at failure was recorded and converted to a tensile stress(MPa). Mean values and standard deviations of the bond strength are listed in table. One-way ANOVA was used to determine significant difference at the 95% level. The bond strength of SBMP and SB were not affected by salivary contamination, but that of UB was significantly affected by salivary contamination. These results indicate that DBSs with total etch technique seems less likely affected by salivary contamination in bonding procedure.

A novel in-situ vacuu encapsulted lateral field emitter triode (자체적으로 진공을 갖는 수평형 전계 방출 트라이오드)

  • 임무섭;박철민;한민구;최연익
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.12
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    • pp.65-71
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    • 1996
  • A novel lateral field emitter triode has been designed and fabricated. It has self-vacuum environmets and low turn-on voltage, so that the chief problems of previous field emission devices such as additional vacuum sealing process and high turn-on voltage are settled. An in-situ vaccum encapsulation empolying recessed cavities by isotropic RIE (reactive ion etch) method and an electron beam evaporated molybdenum vacuum seals are implemented to fabricate the new field emitter triode. The device exhibits low turn-on voltage of 7V, stabel current density of 2.mu.A/tip at V$_{AC}$ = 30V, and high transconductance (g$_{m}$) of 1.7$\mu$S at V$_{AC}$ = 22V. The superb device characteristics are probably due to sub-micron dimension device structure and the pencil type lateral cathode tip employing upper and lower LOCOS oxidation.

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The characteristics of Magnetized plasma and its applications to Etching (자화된 플라즈마의 특성 및 식각에의 응용)

  • Shin, Kyoung-Sop;Lee, Ho-Jun;Whang, Ki-Woong
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.261-263
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    • 1993
  • The effects of the magnetic field and gas pressure on the etching characteristics were investigated in the axial magnetic field enhanced RIE system. This system has many advantages compared with the conventional RIE system ; the capability of operating at low pressure, low self-bias voltage, high electron density and high etch rate in the low pressure, but also has disadvantages such as the nonconformity of plasma density which intensifies as the magnitude of magnetic field increases. To overcome this problem we made some grooved anode and tried to find the optimal pressure and B-field strength.

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$\mu$CP Process Technology for Nanopattern Implementation (나노패턴 구현을 위한 $\mu$CP 공정기술)

  • 조정대;신영재;김광영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.624-627
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    • 2003
  • Microcontact printing (uCP) of alkanethiols on gold was the first representative of soft-lithography processes. This is an attempt to enhance the accuracy of classical to a precision comparable with optical lithography, creating a low-cost, large-area, and high-resolution patterning process. Microcontact printing relies on replication of a pattered PDMS stamp from a master to form an elastic stamp that can be inked with a SAM solution(monolayer -forming ink) using either immersion inking or contact inking. The inked PDMS stamp is then used to print a pattern that selectively protects the gold substrate during the subsequent etch.

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