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We investigated the etching characteristics of hydrogen iodide (HI) neutral beam etching (NBE) of GaN and InGaN and compared with Cl2 NBE. We showed the advantages of HI NBE vs Cl2 NBE, namely: higher InGaN etch rate, better surface smoothness, and significantly reduced etching residues. Moreover, HI NBE was suppressed of yellow luminescence compared with Cl2 plasma. InClx is a product of Cl2 NBE. It does not evaporate and remains on the surface as a residue, resulting in a low InGaN etching rate. We found that HI NBE has a higher reactivity with In resulting in InGaN etch rates up to 6.3 nm/min, and low activation energy for InGaN of approximately 0.015 eV, and a thinner reaction layer than Cl2 NBE due to high volatility of In- I compounds. HI NBE resulted in smoother etching surface with a root mean square average (rms) of 2.9 nm of HI NBE than Cl2 NBE (rms: 4.3 nm) with controlled etching residue. Moreover, the defect generation was suppressed in HI NBE vs. Cl2 NBE, as indicated by lower yellow luminescence intensity increase after etching. Therefore, HI NBE is potentially useful for high throughput fabrication of μLEDs.

We investigated a high electron mobility Ge FinFET fabricated by defect-free and roughness-free atomic layer neutral beam etching (NBE) compared with one fabricated by conventional plasma etching (PE). The etching interface roughness and defect were estimated by high-resolution transmission electron microscopy (TEM). In the case of using atomic layer defect-free NBE, the root-mean-square roughness of the Ge Fin sidewall surface is 1/3 times smaller than that using PE. Then, the electron mobility of Ge FinFET was improved by 1.65 times compared with that of a PE etched FinFET sample. For the subthreshold swing, the defect density of the interface between the Ge and gate dielectric film was improved by NBE. Ioff average currents of NBE and PE were around 18.1 and 57.6 nA/μm, respectively. As a result, NBE reduces the off-leakage current to 1/3 times less than PE. This corresponded to the differences in surface roughness and defect generation between NBE and PE. Therefore, we found that NBE could achieve a good performance by defect-free and atomically-flat etching the surface.

The phonon transport in the lateral direction for gap-controlled Si nanopillar/SiGe interlayer composite materials was investigated to eliminate heat generation in the channel area for advanced MOS transistors. The gap-controlled Si NP/SiGe composite layer showed 1/100 times lower thermal conductivity than Si bulk. Then, the phonon transport behavior in lateral direction could be predicted by the combination between 3-omega measurement method for thermal conductivity and Landauer approach for phonon transport in Si NP/Si0.7Ge0.3 interlayer composite structure. We found that the NP structure could regulate the phonon transport in the lateral direction by changing the NP gaps. As such, this structure achieves the first step toward phonon transport management in the same electron transportation direction of planar-type MOSFETs and represents a promising solution to heat generation for advanced CMOS devices.

We fabricated a highly water-repellent quartz nanopillar (NP) structure to investigate the effect of varying the contact angle (CA) by using 10-nm-order gaps and 10-nm-diameter NPs. Gaps from 15 to 30 nm led to CAs of more than 100°, showing hydrophobicity, to a maximum of 105°. The mechanism of repelling water on quartz could be explained by the Cassie-Baxter model with a filling factor. A gap of more than 30 nm fills with water due to capillarity, but a gap of less than 30 nm causes water to be repelled by air. We were able to repeatedly fabricate a quartz NP structure with a controllable gap by using a combination of a bio-template and neutral-beam etching and found this structure to be highly water-repellent. The structure has high durability and optical transparency. As a result, we conclude that it can be used in sensors and lenses on various devices such as cameras and radars.

Peri-implantitis is one of the most common complications after dental implant placement. Researchers have demonstrated that the peri-implantitis tends to occur around dental implants with a rough surface rather than those with a smooth surface. We aimed to investigate the ability of a smooth titanium (Ti) surface containing strontium (Sr) to enhance bone formation as a result of strontium's capacity to support osteoblast proliferation and differentiation. A thin titanium oxide film was formed on an as-mirror polished Ti surface by dipping in 5% sodium hypochlorite (NaOCl) solution for 24 h, followed by thermal treatment at 350°C. The Ti surface was then treated with 1% strontium nitrate (Sr(NO

This study was to elucidate the surface characteristics and in vitro cell behaviors of biomedical titanium (Ti) with the biofunctional surface (nanostructured rutile-Ti dioxide (NanoR-TiO2) layer combined with amino-groups (NH2) and albumin). Biofunctional surface features were analyzed via scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. Immunolabeling with nano-gold particles was used to reflect the expected specific binding of protein on the biofunctional surface. In vitro cell behaviors were evaluated by culturing with mouse pre-osteoblastic cell line (MC3T3-E1) at 37 °C in different periods. Analytical results indicated that the sandwich-like (NH2/NanoR-TiO2/Ti) layer was formed on the Ti surface after plasma oxidation and polymerization. Immunolabeling analysis results also proved that the albumin can be successfully bonded with NH2 on NanoR-TiO2 layer. Moreover, cell morphology observation revealed that the biofunctional surface could potentially facilitate cell adhesion and proliferation. Therefore, the biomedical Ti with the biofunctional surface is a promising biomaterial for dental implant applications.

X-ray photoelectron spectroscopy (XPS) is used to analyze 4-META resin and enamel that are debonded at an adhesive interface. The XPS spectra showed two chemical states for Ca: one resulted from Ca of hydroxyapatite and the other, an unknown chemical state, suggested that Ca was chemically bonded with 4-META. We postulate that for a chemical reaction of 4-META and hydroxyapatite, the chemical structure of carboxyl groups will resemble that of calcium phthalate. Hence, calcium phthalate was used as a reference material. Additionally, the spectra obtained from the adhesive interface and the mixture of calcium phthalate with hydroxyapatite particles were compared using peak deconvolution analysis. XPS analysis revealed that the chemical bond of 4-META with enamel resembled the chemical state of Ca in calcium phthalate. Consequently, we suggest that Ca of the enamel and the carboxyl group of 4-META were chelate-bonded at the interface.

This study was aimed at investigating the protective effects of glass ionomer cement (GIC) and surface pre-reacted glass ionomer (S-PRG) fillers used as dental restorative materials on demineralization of bovine enamel. GlasIonomer FX ULTRA (FXU), Fuji IX GP Extra (FIXE), CAREDYNE RESTORE (CDR) were used as GICs. PRG Barrier Coat (BC) was used as the S-PRG filler. They were incubated in a lactic acid solution (pH = 4.0) for six days at a temperature of 37 &deg, C. The mineral was etched from the enamel surface, and a large number of Ca and P ions were detected in solution. The Al, F, Na, Sr, and Sr ions were released in GICs and S-RPG fillers. The Zn ion was released only in CDR and the B ion was released only in BC. The presence of apparent enamel prism peripheries was observed after six days of treatment for the group containing only enamel blocks. pH values for the FXU, FIXE, CDR, BC, and enamel block groups after six days were 6.5, 6.6, 6.7, 5.9, and 5.1, respectively. Therefore, the observed pH neutralization effect suppressed progression of caries due to the release of several ions from the restoratives.

Studies examining the effect of operator experience on the accuracy of static guided implant surgery have used postoperative computed tomography (CT) images to measure the error, with inconsistent results. The purpose of this study was to try to clarify this issue by using a measurement method based on the postoperative optical scan. Thirty dentists were divided into an experienced group and an inexperienced group. On a partially edentulous mandibular model in the manikin head, each dentist placed three implants via the stereolithographic (SLA) surgical guide. The implant positions were identified by a desktop scanner and compared with the planned positions using a metrology software program. No statistically significant differences were observed for any of the measured positional and angular deviations of the three implant sites between experienced and inexperienced operators (p &gt, 0.01). All the mean values of deviations of the inexperienced group, except the depth deviation, were less than the experienced group. Implants inserted by dentists under 40 years old had significantly better accuracy than senior doctors in the global deviation at implant apex (p = 0.006). Within the limits of this study, we concluded that operator experience is not a critical factor in achieving the accuracy of guided implant surgery via the tooth-supported SLA surgical guide. Large deviations could occur even with the aid of the SLA surgical guide, and care must be taken to avoid errors for both experienced and inexperienced operators.

We investigated the surface modification of orthodontic stainless steel wire using electrophoretic deposition (EPD) of bioactive glass (BG). BG coatings were characterized by spectrophotometry, three-dimensional (3D) focal laser scanning microscopy and scanning electron microscopy. The mechanical properties of the BG-coated wires were estimated nanoindentation, three-point bending and drawing friction tests. BG-coated specimens prepared at higher voltage showed higher values for both reflectance and L* compared to those prepared at lower voltage. Specimens coated at higher voltage had significantly lower surface roughness than those coated at lower voltage, and their BG layers had higher hardness and elastic modulus values. In the three-point bending test, BG-coated wires produced significantly lower elastic modulus than non-coated wires. Most BG-coated specimens produced similar frictional forces to those produced by non-coated specimens. The surface modification technique applying EPD and BG coating to orthodontic stainless steel wire could be used to develop new esthetical orthodontic wire.

This study developed a promising approach (low-temperature plasma polymerization with allylamine) to modify the titanium (Ti) surface, which helps the damaged tissue to heal faster. The Ti surface was first cleaned by argon (Ar) plasma, and then the functional amino-groups were coated on the Ti surface via plasma polymerization. The topography characteristics, wettability, and optimal plasma modification parameters were investigated through atomic force spectroscopy, secondary ion mass spectroscopy, and response surface methodology (RSM). Analytical results showed that the formation of a porous surface was found on the Ar plasma-modified Ti surfaces after Ar plasma modification with different parameters. The Ar plasma modification is an effective approach to remove surface contaminants and generate a porous topography on the Ti surface. As the Ti with Ar plasma modification was at 100 W and 190 m Torr for 12 min, the surface exhibited the maximum hydrophilic performance. In the allylamine plasma modifications, the contact angle values of the allylamine plasma-modified Ti surfaces varied between 70.15&deg, and 88.26&deg, in the designed parameters. The maximum concentration of amino-groups (31.58 nmole/cm2) can be obtained from the plasma-polymerized sample at 80 W and 150 mTorr for 22 min. Moreover, the cell response also demonstrated that the allylamine plasma-modified Ti sample with an optimal modification parameter (80 W, 22 min, and 150 mTorr) possessed great potential to increase cell adhesion ability. Thus, the optimal parameters of the low-temperature plasma polymerization with allylamine can be harvested using the RSM design. These data could provide new scientific information in the surface modification of Ti implant.

This paper describes the use of flash lamp annealing (FLA) to fabricate high-Sn content GeSn n-MOSFETs. We exploit FLA processing for both impurity activation and for the solid-phase growth (SPG) of the GeSn channel. High-Sn incorporation of up to 12% is achieved by overcoming the solid-solubility limit of Sn in Ge (1%), and high-quality n+-source/drain junctions were obtained by P implantation and subsequent FLA. Consequently, we achieved well-behaved transistor operation of the SPG-Ge0.88Sn0.12 n-MOSFETs, with an on/off current ratio one order of magnitude higher than for conventional rapid thermal annealing processing.

The aim of this study was to improve the cytocompatibility and differentiation of human bone marrow-derived mesenchymal stem cells on the surface of titanium implants by immobilizing biofunctional molecules on their surface. Gly-Arg-Gly-Asp-Ser (GRGDS) peptides, human plasma fibronectin (pFN), or type I collagen from calf skin (Col) was covalently immobilized on the titanium surfaces. Twice as many cells attached to the Col- and pFN-immobilized titanium surfaces than attached to the as-polished surface control. The ALP activity of the cells, as well as the mineralized nodule formation, was significantly higher on the Col- and pFN-immobilized titanium surfaces than on the as-polished surfaces. These results indicate that the immobilization of biofunctional molecules such as Col and pFN on titanium surfaces enhances the attachment, spreading, proliferation, and differentiation of human bone marrow-derived mesenchymal stem cells, which may lead to a more rapid bone-titanium integration.

We fabricated high aspect ratio 10-nm Si nanopillar (NP) array structures with a few-tenths-nm-gap arranged by fusing biotemplate and neutral beam etching processes to investigate the wettability [e.g., contact angle (CA)] with and without surface silicon oxide film. The NP array with silicon native oxides in all gaps exhibited super-hydrophilicity due to the chemical liquid-solid interface interaction and larger surface area than the Si flat surface thanks to the NP structure. These phenomena can be explained by using the Wenzel model. In contrast, when we selectively removed the native oxide on Si NP surface with our radical treatment, a gap variation from 11 to 43 nm stably resulted in a CA of more than 96° (hydrophobicity) with a maximum of 115°. This can be explained by using the Cassie–Baxter model with a filling factor. Our findings demonstrate that controlled surface wettability can be achieved by combining our controllable gap silicon NP array structures and the surface with or without silicon native oxides. The gap of a Si NP fills with water due to the capillarity on a silicon native oxide, but on a pure stable silicon one with a defect-free surface, does not completely fill. We found that Si NP structures with controllable gaps exhibit a surface wettability ranging from super-hydrophilicity to high-hydrophobicity.

The effect of flash lamp annealing on the crystal growth of amorphous germanium-tin (GeSn) layer deposited on Ge-on-insulator wafer was investigated. It was found that the presence of Sn in the amorphous Ge significantly promoted solid-phase growth (SPG). The diffusion of Sn during the SPG of GeSn was completely suppressed owing to milli-second thermal processing, providing a high-quality GeSn layer with Sn content of 13%, which far exceeds the equilibrium solid solubility limit (∼1%). The fabricated GeSn/Ge-on-insulator wafer exhibited improved infrared absorption beyond 2000 nm, which would be a suitable platform for near-infrared image sensors based on group-IV materials.

A distal free-end situation could result in insufficient stability of the surgical guide, and could reduce accuracy of the static guided implant surgery (sGIS). The purpose of this study was to investigate the accuracy of sGIS using a combination tooth-and-bone supported stereolithographic (SLA) surgical guide in distal extension situation. Thirty dentists, each placed three implants at the Federal Dentaire Internationale (FDI) teeth positions #46, #47 (a distal extension situation), and #36 (a single tooth gap) via the surgical guide on a model fixed to a manikin. Pre- and post-operative computed tomography (CT) images of the models were superimposed, and the positional and angular deviations of the implants were measured with metrology software. An analysis of variance (ANOVA) test was performed to evaluate the intergroup differences. No significant differences were found for all the positional and angular deviations among the three implant sites, except the bucco-lingual deviation at the implant platform in the #47 position (0.43 &plusmn, 0.19 mm) that was significantly larger than the #46 (0.21 &plusmn, 0.14 mm) and #36 (0.24 &plusmn, 0.25 mm) positions (p &lt, 0.0001). Within the limits of this study, we conclude that, in distal extension situation of missing mandibular molars, adding a bone-supported strut in the distal part of the surgical guide can be beneficial to the accuracy of the sGIS.

Hydroxyapatite (HA) coatings on titanium implants enhance rapid bone formation around the implant due to their osteoconductive property. The present study aimed to achieve a thin and uniform HA film coating on titanium implants by solution plasma treatment (SPT). Commercially pure titanium and porous titanium disks were employed. A pulse plasma generator was used on the disks for 30 min. Morphologic and crystallographic features of the deposited films were examined by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). To evaluate the wettability of the disks, water droplet (20 &micro, L) surfaces were measured using a contact angle analyzer. The initial attachment of osteoblast-like cells (MC3T3E1) on the titanium substrates before and after solution plasma treatment was evaluated by counting the number of attached cells after incubation for 4 h. After immersion in the mineralizing solution for up to seven days, no crystals were observed on the polished-Ti surface. A more uniform and dense precipitation of round and grown crystals with diameters of approximately 1&ndash, 5 &micro, m was observed on Ti-SPT. XRD clearly showed that the precipitated crystals on titanium disks were HA. The contact angle of the polished-Ti increased with time (&theta, = 37&deg, &ndash, 51&deg, ). The surface of the Ti-SPT remained hydrophilic (&theta, ˂ 5&deg, ) after up to 30 days of aging. The number of attached cells on the Ti-SPT after aging for 30 days remained above 85% of that on the Ti-SPT without aging. SPT in a mineralizing solution can be used to acquire a homogenous precipitation of HA on porous-surfaced titanium implants.

Background Neuroendocrine tumors (NETs) of the gallbladder are rare and generally considered low-grade malignancies. We herein describe a case of a patient with a 0.8-cm clear cell NET G1 of the gallbladder with nodal involvement. Case presentation A 65-year-old man with no medical history indicative of von Hippel-Lindau (VHL) disease underwent laparoscopic cholecystectomy for cholecystolithiasis. There was a 0.8-cm tumor in the neck of the gallbladder. Histologic examination revealed nests or trabecular growth of clear cells with small round-to-oval nuclei. Immunohistochemically, tumor cells showed positivity for chromogranin A and synaptophysin; Ki-67 index was

The aim of this study was to examine the effect of NaOCl pretreatment on the biomechanical fixation of implant at the early healing stage of a rat model. Polished titanium cylindrical implants and disks were prepared, and one-half of these samples were dual acidetched. Then, one-half of both surfaces were chemically-cleaned by pretreatment with 5% NaOCl solution for 24 h. Morphological analyses showed that there was no significant difference between before and after NaOCl treatment. The wettability measurement demonstrated that NaOCl treatment secondarily converted both titanium surfaces from hydrophobic to superhydrophilic, accompanied by the removal of hydrocarbons from the titanium surfaces. Biomechanical push-in test indicated that the bone-titanium integration strength of the NaOCl-treated implants were significantly greater than that of the untreated implants (p

We investigated the effects of CO2 laser irradiation combined with acidulated phosphate fluoride (APF) application on the demineralization of enamel. APF gel was applied to the buccal enamel of human premolars and CO2 laser was applied. After the specimens were immersed in demineralization solution for 72 h, they were subjected to depth-dependent micro-CT and nanoindentation analyses. Micro-X-ray diffraction and X-ray photoelectron spectroscopy were performed to analyze the surfaces. Some surface regions of the enamel in specimens that were laser-irradiated with low output and APF-treated showed significantly higher values of MD and hardness than specimens treated with APF alone. A higher fluoride concentration in the enamel surface was observed in specimens treated with CO2 laser irradiation plus APF gel application. In conclusion, CO2 laser irradiation with low output is preferable to improve acid resistance.

This study investigated the surface modification of orthodontic stainless steel using electrophoretic deposition (EPD) of bioactive glass (BG). The BG coatings were characterized by spectrophotometry, scanning electron microscopy with energy dispersive X-ray spectrometry, and X-ray diffraction. The frictional properties were investigated using a progressive load scratch test. The remineralization ability of the etched dental enamel was studied according to the time-dependent mechanical properties of the enamel using a nano-indentation test. The EPD process using alternating current produced higher values in both reflectance and lightness. Additionally, the BG coating was thinner than that prepared using direct current, and was completely amorphous. All of the BG coatings displayed good interfacial adhesion, and Si and O were the major components. Most BG-coated specimens produced slightly higher frictional forces compared with non-coated specimens. The hardness and elastic modulus of etched enamel specimens immersed with most BG-coated specimens recovered significantly with increasing immersion time compared with the non-coated specimen, and significant acid-neutralization was observed for the BG-coated specimens. The surface modification technique using EPD and BG coating on orthodontic stainless steel may assist the development of new non-cytotoxic orthodontic metallic appliances having satisfactory appearance and remineralization ability.

The scaled charge trapping (CT) type silicon on insulator (SOI) FinFET flash memories with different blocking layer materials of Al2O3 and SiO2 have successfully been fabricated, and their electrical characteristics including short-channel effect (SCE) immunity, threshold voltage (Vt) variability, and the memory characteristics have been comparatively investigated. It was experimentally found that the better SCE immunity and a larger memory window are obtained by introducing a high-k Al2O3 blocking layer instead of a SiO2 blocking layer. It was also confirmed that the variability of Vt before and after one program/erase (P/E) cycle is almost independent of the blocking layer materials.

The authors developed extremely selective etching for making an atomically flat, defect-free germanium fin (Ge Fin) structure. The etching uses a hydrogen bromide (HBr) neutral beam (NB), and they investigated the etching reaction differences between the HBr NB and a Cl2 NB. No sidewall etching by HBr NB occurred at 90 °C, although that by Cl2 NB occurred at more than 90 °C. This was due to the different boiling points of GeBr4 and GeCl4 as the reacted layer was formed by NB irradiation on the Ge surface. As a result, the Ge sidewall etching by Cl2 NB occurred above 90 °C, whereas that by HBr NB did not occur at 90 °C. Additionally, nonvolatile bromide protected layers, such as GeBr4 and SiBrxOy, were deposited on the Ge sidewall and the SiO2 top surface in case of using HBr, respectively. Then, the authors succeeded in fabricating the atomically flat, defect-free Ge Fin structure with the extremely selective HBr NB etching. This result shows that HBr NB can more precisely achieve sub-10-nm scale atomic layer Ge etching for 3D Fin-type MOSFETs.

In case of using pure chlorine chemistry, Ge etching reactivity is three times higher than Si etching reactivity because of the larger lattice spacing in Ge. As a result, during the chlorine plasma etching of a Ge Fin structure, there are serious problems such as a large side-etching and large surface roughness on the Ge sidewall. Conversely, the authors found that several-ten nanometer-width Ge Fin structures with defect-free, vertical, and smooth sidewalls were successively delineated by chlorine neutral beam etching. Based on these results, the problems caused by chlorine plasma etching are considered to be due to the enhancement of chemical reactivity caused by defect on the sidewall with the irradiation of ultraviolet/vacuum ultra violet (UV/VUV) photons. Namely, it is clarified that the neutral beam etching could achieve real atomic layer etching by controlling the defect without any UV/VUV photons on the sidewall surface for future nanoscale Ge Fin structures.In case of using pure chlorine chemistry, Ge etching reactivity is three times higher than Si etching reactivity because of the larger lattice spacing in Ge. As a result, during the chlorine plasma etching of a Ge Fin structure, there are serious problems such as a large side-etching and large surface roughness on the Ge sidewall. Conversely, the authors found that several-ten nanometer-width Ge Fin structures with defect-free, vertical, and smooth sidewalls were successively delineated by chlorine neutral beam etching. Based on these results, the problems caused by chlorine plasma etching are considered to be due to the enhancement of chemical reactivity caused by defect on the sidewall with the irradiation of ultraviolet/vacuum ultra violet (UV/VUV) photons. Namely, it is clarified that the neutral beam etching could achieve real atomic layer etching by controlling the defect without any UV/VUV photons on the sidewall surface for future nanoscale Ge Fin structures.

A rigorous analytical thermal model has been formulated for the analysis of self-heating effects in FinFETs, under both steady-state and transient stress conditions. 3-D self-consistent electrothermal simulations, tuned with experimentally measured electrical characteristics, were used to understand the nature of self-heating in FinFETs and calibrate the proposed model. The accuracy of the model has been demonstrated for a wide range of multifin devices by comparing it against finite element simulations. The model has been applied to carry out a detailed sensitivity analysis of self-heating with respect to various FinFET parameters and structures, which are critical for improving circuit performance and electrical overstress/electrostatic discharge (ESD) reliability. The transient model has been used to estimate the thermal time constants of these devices and predict the sensitivity of power-to-failure to various device parameters, for both long and short pulse ESD situations. Suitable modifications to the model are also proposed for evaluating the thermal characteristics of production level FinFET (or Tri-gate FET) structures involving metal-gates, body-tied bulk FinFETs, and trench contacts.

With the continuous progress in nanomaterial development for biomedicine, the potential cytotoxicity of nanoparticles is drawing more attention and concern for clinical applications. The purpose of this study was to evaluate biological responses of new water-dispersible silver nanoparticles (Ag-NPs) stabilized by Ag-C σ-bonds in cultured murine macrophages (RAW264.7) and osteoblast-like cells (MC3T3-E1) using cell viability and morphological analyses. For RAW264.7, Ag-NPs seemed to induce cytotoxicity that was dependent on the Ag-NP concentration. However, no cytotoxic effects were observed in the MC3T3-E1 cell line. In microscopic analysis, Ag-NPs were taken up by MC3T3-E1 cells with only minor cell morphological changes, in contrast to RAW264.7 cells, in which particles aggregated in the cytoplasm and vesicles. The ability of endocytosis of macrophages may induce harmful effects due to expansion of cell vesicles compared to osteoblast-like cells with their lower uptake of Ag-NPs.

The residual stress caused by polymerization shrinkage and thermal contraction of a heat-curing resin containing 4-META on a metal-resin structure was measured by a scanning acoustic microscope. The tensile residual stress in the resin occurred within 70 µm of the adhesion interface with a flat plate specimen. The maximum tensile stress was about 58 MPa at the interface. On a metal plate specimen with retention holes, ring-like cracks in the resin occurred around the retention holes with the adhesive specimen and many linear cracks occurred in the resin vertical to the longitudinal direction of the metal frame with the non-adhesive specimens. There was tensile residual stress on the resin surface at the center of the retention holes of the adhesion specimen, indicating that the stress in the specimen with surface treatment for adhesion was higher than in that without surface treatment.

OBJECTIVE: To determine if a new experimental resin-based material containing Portland cement (PC) can help prevent enamel caries while providing adequate shear bond strength (SBS). MATERIALS AND METHODS: Brackets were bonded to human premolars with experimental resin-based adhesive pastes composed of three weight rations of resin and PC powder (PC 30, 7∶3; PC 50, 5∶5; PC 70, 3∶7; n = 7). Self-etching primer (SEP) adhesive (Transbond Plus) and resin-modified glass ionomer cement (RMGIC) adhesive (Fuji Ortho FC Automix) were used for comparison. All of the bonded teeth were subjected to alternating immersion in demineralizing (pH 4.55) and remineralizing (pH 6.8) solutions for 14 days. The SBS for each sample was examined, and the Adhesive Remnant Index (ARI) score was calculated. The hardness and elastic modulus of the enamel were determined by a nanoindenter at 20 equidistant depths from the external surface at 100 µm from the bracket edge. Data were compared by one-way analysis of variance and a chi-square test. RESULTS: PC 50 and PC 70 showed significantly greater SBS than Fuji Ortho FC Automix, although Transbond Plus showed significantly greater SBS than other bonding systems. No significant difference in the ARI category was observed among the five groups. For specimens bonded with PC 50 and PC 70, the hardness and elastic modulus values in most locations were equivalent to those of Fuji Ortho FC Automix. CONCLUSIONS: Experimental resin-based bonding material containing PC provides adequate SBS and a caries-preventive effect equivalent to that of the RMGIC adhesive system.

ON-current (Ion) variability is comprehensively investigated for fin-shaped FETs (FinFETs) by measurement-based analysis. Variation sources of Ion are successfully extracted as independent contributions of threshold voltage Vt, transconductance Gm, and parasitic resistance Rpara. As well as Vt variability, Gm variation exhibits a linear relationship in the Pelgrom plot. However, the Gm variation is not reduced with scaling the gate dielectric thickness unlike the Vt variation. Perspective for 14-nm FinFETs represents that the Gm variation will be the dominant Ion variation source. A solution to reduce the Gm variation for the FinFET is also proposed.

A correlation between the characteristics of the 30-nm LG fin-shaped field-effect transistors and the static random-access memory performance is precisely studied. By investigating an effect of the Vth variation to the static noise margin (SNM) variation of two different memory states of the storage node, it is revealed that the Vth variations of the pull-up, pull-down, and pass-gate transistors correlate with the SNM. Moreover, the contribution and the severity of each transistor variation to σSNM are clarified.