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Human genetic variants are associated with many traits through largely unknown mechanisms. Here, combining approximately 260,000 Japanese study participants, a Japanese-specific genotype reference panel and statistical fine-mapping, we identified 4,423 significant loci across 63 quantitative traits, among which 601 were new, and 9,406 putatively causal variants. New associations included Japanese-specific coding, splicing and noncoding variants, exemplified by a damaging missense variant rs730881101 in TNNT2associated with lower heart function and increased risk for heart failure (P= 1.4 × 10−15and odds ratio = 4.5, 95% confidence interval = 3.1–6.5). Putative causal noncoding variants were supported by state-of-art in silico functional assays and had comparable effect sizes to coding variants. A plausible example of new mechanisms of causal variants is an enrichment of causal variants in 3′ untranslated regions (UTRs), including the Japanese-specific rs13306436 in IL6associated with pro-inflammatory traits and protection against tuberculosis. We experimentally showed that transcripts with rs13306436 are resistant to mRNA degradation by regnase-1, an RNA-binding protein. Our study provides a list of fine-mapped causal variants to be tested for functionality and underscores the importance of sequencing, genotyping and association efforts in diverse populations.

IMPORTANCE: Vasospastic angina (VSA) is vasospasm of the coronary artery and is particularly prevalent in East Asian populations. However, the specific genetic architecture for VSA at genome-wide levels is not fully understood. OBJECTIVE: To identify genetic factors associated with VSA. DESIGN, SETTING, AND PARTICIPANTS: This was a case-control genome-wide association study of VSA. Data from Biobank Japan (BBJ; enrolled patients from 2002-2008 and 2013-2018) were used, and controls without coronary artery disease (CAD) were enrolled. Patients from the BBJ were genotyped using arrays or a set of arrays. Patients recruited between 2002 and 2005 were classified within the first dataset, and those recruited between 2006 and 2008 were classified within the second dataset. To replicate the genome-wide association study in the first and second datasets, VSA cases and control samples from the latest patients in the BBJ recruited between 2013 and 2018 were analyzed in a third dataset. EXPOSURES: Single-nucleotide variants associated with VSA. MAIN OUTCOMES AND MEASURES: Cases with VSA and controls without CAD. RESULTS: A total of 5720 cases (mean [SD] age, 67 [10] years; 3672 male [64.2%]) and 153 864 controls (mean [SD] age, 62 [15] years; 77 362 male [50.3%]) in 3 datasets were included in this study. The variants at the RNF213 locus showed the strongest association with VSA across the 3 datasets (odds ratio [OR], 2.34; 95% CI, 1.99-2.74; P = 4.4 × 10−25). Additionally, rs112735431, an Asian-specific rare deleterious variant (p.Arg4810Lys) experimentally shown to be associated with reduced angiogenesis and a well-known causal risk for Moyamoya disease was the most promising candidate for a causal variant explaining the association. The effect size of rs112735431 on VSA was distinct from that of other CADs. Furthermore, homozygous carriers of rs112735431 showed an association with VSA characterized by a large effect estimate (OR, 18.34; 95% CI, 5.15-65.22; P = 7.0 × 10−6), deviating from the additive model (OR, 4.35; 95% CI, 1.18-16.05; P = .03). Stratified analyses revealed that rs112735431 exhibited a stronger association in males (χ21 = 7.24; P = .007) and a younger age group (OR, 3.06; 95% CI, 2.24-4.19), corresponding to the epidemiologic features of VSA. In the registry, carriers without CAD of the risk allele rs112735431 had a strikingly high mortality rate due to acute myocardial infarction during the follow-up period (hazard ratio, 2.71; 95% CI, 1.57-4.65; P = 3.3 × 10−4). As previously reported, a possible overlap between VSA and Moyamoya disease was not found. CONCLUSIONS AND RELEVANCE: Results of this study suggest that vascular cell dysfunction mediated by variants in the RNF213 locus may promote coronary vasospasm, and the presence of the risk allele could serve as a predictive factor for the prognosis.

ABSTRACTAnimals adapt to their environments in the course of evolution. One effective approach to elucidate mechanisms of adaptive evolution is to compare closely related species with model organisms in which knowledge of the molecular and physiological bases of various traits has been accumulated. Drosophila elegansand its close relatives, belonging to the same species group as the model organism D. melanogaster, exhibit various unique characteristics such as flower-breeding habit, courtship display, territoriality, sexual dimorphism, and colour polymorphism. Their ease of culturing and availability of genomic information makes them a useful model for understanding mechanisms of adaptive evolution. Here, we review the morphology, distribution, and phylogenetic relationships of D. elegansand related species, as well as their characteristic flower-dependent biology, food habits, and life-history traits. We also describe their unique mating and territorial behaviours and note their distinctive karyotype and the genetic mechanisms of morphological diversity that have recently been revealed.

Lacrimal glands are the main exocrine glands of the eyes. Situated within the orbit, behind the upper eyelid and towards the temporal side of each eye, they secrete lacrimal fluid as a major component of the tear film. Here we identify cells with characteristics of lacrimal gland primordia that emerge in two-dimensional eye-like organoids cultured from human pluripotent stem cells1. When isolated by cell sorting and grown under defined conditions, the cells form a three-dimensional lacrimal-gland-like tissue organoid with ducts and acini, enabled by budding and branching. Clonal colony analyses indicate that the organoids originate from multipotent ocular surface epithelial stem cells. The organoids exhibit notable similarities to native lacrimal glands on the basis of their morphology, immunolabelling characteristics and gene expression patterns, and undergo functional maturation when transplanted adjacent to the eyes of recipient rats, developing lumina and producing tear-film proteins.

Systemic sclerosis is an autoimmune disease characterized by generalized fibrosis in connective tissues and internal organs as consequences of microvascular dysfunction and immune dysfunctions, which leads to premature death in affected individuals. The etiology of systemic sclerosis is complex and poorly understood, but as with most autoimmune diseases, it is widely accepted that both environmental and genetic factors contribute to disease risk. During the last decade, the number of genetic markers convincingly associated with systemic sclerosis has exponentially increased. In this article, we briefly mention the genetic components of systemic sclerosis. Then, we review the classical and novel genetic associations with systemic sclerosis, analyzing the firmest and replicated signals within non–human leukocyte antigen genes, identified by both candidate gene approach and genome-wide association studies. We also provide an insight into the future perspectives that will shed more light into the complex genetic background of the disease. Despite the remarkable advance of systemic sclerosis genetics during the last decade, the use of the new genetic technologies such as next-generation sequencing, as well as the deep phenotyping of the study cohorts, to fully characterize the genetic component of this disease is imperative to identify causal variants, which leads to more targeted and effective treatment of systemic sclerosis.

A Tf2NH-catalyzed aza-Ferrier reaction of N,O-allenyl acetals was reported. This protocol provided various types of β-amino-α-methylene aldehydes as the products. The N,O-allenyl acetal substrates were easily prepared by base-induced isomerization of N,O-propargyl acetals with Triton B. The N,O-propargyl acetals were prepared from the corresponding aldehydes or lactams. Further synthetic applications of the products were also described.

ABSTRACTAlthough fluctuations in energy metabolism are known to influence intake as well as nutrient selection, there are no definitive reports on how food preferences change with changes in habitat temperature. We investigated the effects of habitat temperature on appetite and food preference and elucidated the underlying mechanism by conducting a feeding experiment and a leptin administration test on mice reared at low temperatures. Our results showed that the increased food intake and HFD preference observed in the 10°C group were induced by decrease in plasma leptin concentration. Then, a leptin administration experiment was conducted to clarify the relationship between leptin and food preference with low-temperature acclimation. The control group reared in 10°C significantly preferred the HFD, but the leptin-administered group did not. These results show that the peripheral system appetite-regulating hormone leptin not only acts to suppress appetite but also might inhibit preference for lipids in low-temperature acclimation.

Ergothioneine-rich crude extracts of Pleurotus cornucopiaewere used as a source of antioxidative components to control the effects of lipid oxidation in astaxanthin-containing liposomes. This study aimed to elucidate the interactions of liposomal astaxanthin and lipids with ergothioneine-rich mushroom extract (ME) under radical oxidation-induced conditions to provide a better understanding of the agricultural and postharvest applications of this strategy. Azo compounds (2,2′-azobis(2-methylpropionamidine) dihydrochloride and 2,2′-azobis(2,4-dimethylvaleronitrile) were used as hydrophilic and lipophilic radical initiators, respectively. Results of this study demonstrate that the presence of ME significantly delayed the oxidative degradation of astaxanthin and controlled the progress of lipid oxidation in a liposomal system. The lipid hydroperoxide formation was significantly suppressed, while polyunsaturated fatty acids were protected from degradation. In addition, Crude ME also demonstrated more potent DPPH radical scavenging activities and EC50than the equimolar concentrations of ergothioneine alone, which suggested the presence of additional compounds with antioxidative properties.

We investigated the consistency of four methods by analyzing the distorted Debye rings with various stress states. Firstly, the distorted Debye rings were generated under various uni-, bi-and tri-axial stress states by using the fundamental stress-strain relationship in two dimensional X-ray stress analysis theory. Secondly, we performed reverse analysis of stress states in the frameworks of sin2ψ and cosα methods from the simulated Debye rings. Moreover, the profiles of simulated Debye rings were Fourier transformed and the stress states were calculated in accordance with the obtained 1st and 2nd order Fourier coefficients. As a result, it was confirmed that all these methods provide the same stress values. That is to say, all these methods are consistent. Therefore, we can guarantee the validity of choosing any appropriate method considering the geometrical restrictions of experiment.

We describe a protocol for the generation of a functional and transplantable corneal epithelium derived from human induced pluripotent stem (iPS) cells. When this protocol is followed, a proportion of iPS cells spontaneously form circular colonies, each of which is composed of four concentric zones. Cells in these zones have different morphologies and immunostaining characteristics, resembling neuroectoderm, neural crest, ocular-surface ectoderm, or surface ectoderm. We have named this 2D colony a 'SEAM' (self-formed ectodermal autonomous multizone), and previously demonstrated that cells within the SEAM have the potential to give rise to anlages of different ocular lineages, including retinal cells, lens cells, and ocular-surface ectoderm. To investigate the translational potential of the SEAM, cells within it that resemble ocular-surface epithelia can be isolated by pipetting and FACS sorting into a population of corneal epithelial-like progenitor cells. These can be expanded and differentiated to form an epithelial layer expressing K12 and PAX6, and able to recover function in an animal model of corneal epithelial dysfunction after surgical transplantation. The whole protocol, encompassing human iPS cell preparation, autonomous differentiation, purification, and subsequent differentiation, takes between 100 and 120 d, and is of potential use to researchers with an interest in eye development and/or ocular-surface regeneration. Experience with human iPS cell culture and sorting via FACS will be of benefit for researchers performing this protocol.

A protocol has been developed to use human induced pluripotent stem cells to obtain a self-formed ectodermal autonomous multizone, which includes distinct cell lineages of the eye, including the ocular surface ectoderm, lens, neuro-retina, and retinal pigment epithelium that can be expanded to form a functional corneal epithelium when transplanted to an animal model of corneal visual impairment.

Platinum complexes with 1,4,7-triazacyclononane (tacn) as facial ligands, [PtIVCl3(tacn)](ClO4), [PtIVCl(bpy)(tacn)](ClO4)3([1](ClO4), and [2](ClO4)3, bpy: 2,2′-bipyridine) were prepared, and their hexa-coordinated octahedral structures were determined via single-crystal X-ray analysis. In aqueous solutions containing NaCl as the electrolyte, [2]3+exhibited a quasi-reversible two-electron redox wave at +0.22 V (vs. SCE) with a large peak separation (ΔE= Epc− Epa= 0.28 V). In addition, controlled-potential reduction of [2]3+at −0.30 V in aqueous solutions containing NaCl afforded [PtII(bpy)(tacn)]2+([3]2+), which was then re-oxidized to regenerate [2]3+. X-ray analysis of [3]2+revealed a tetra-coordinated square-planar structure in which both tacn and bpy were bound to the central Pt as bidentate ligands. The redox potential of this reaction is coupled with dissociation/association of Cl−from/to Pt in the solution. MO/DFT calculations indicate that structural changes in tacn promote the reversible two-electron redox reaction between the octahedral Pt(IV) and square planar Pt(II) complexes.

A magneto-optical study of chemically modified magnetite (Fe3O4) nanoparticles is presented with magnetic circular dichroism (MCD) spectroscopy. The magnetite nanoparticles are synthesized using the high-temperature solution reduction of Fe(III) acetylacetonate in the presence of oleylamine. The size of the magnetite nanoparticles examined is 3–4 or 7–8 nm. In contrast to broad and featureless UV–vis–NIR absorption spectra for these magnetite nanoparticles, the MCD responses are much more structured. MCD essentially corresponds to electronic transitions in the absorption spectrum, so to decode electronic transitions in the magnetite nanoparticles and to compare them with those in the bulk phase, simultaneous deconvolution analyses of both the electronic absorption and MCD spectra are conducted, giving accurate transition energies with enhanced spectral resolution. The decomposed transitions are successfully assigned on the basis of the theoretical band structure calculations previously reported. Then the relative absorption and MCD intensities of some deconvoluted bands associated with LMCT or ISCT transitions are found to be size dependent, which can be due to partial surface hydration and/or oxidation of the magnetite nanoparticles. We also compare the magneto-optical responses of magnetite nanoparticles and those of bulk Fe3O4calculated.

For medical or sports applications, human motor control is frequently analyzed. This study focuses on dart throwing motion and investigate the human motor skill to achieve precision control and force generation. The joint coordination is related to stability and accuracy of movements for precision control. On the other hand, the joint correlation is related to transfer of forces and movements for force generation. Uncontrolled manifold (UCM) analysis was applied to evaluate the joint coordination and elucidate the joint which the throwers decrease the variability. In the experiment, ten young people who did not play dart on regular basis participated and performed dart throws at five different throwing distances. Based on the result of UCM analysis, it was found that throwers had less variability on the finger position rather than wrist, elbow, and shoulder positions. In order to evaluate the joint correlation, normalized correlation coefficient between arm and lower body was computed at different throwing distances. This analysis showed that the correlation between elbow and ankle, and between elbow and knee, were increased at long throwing distance. From our results, in dart throwing motion, we elucidated that the longer throw induced the new motor control strategy of precision control and force generation.

Polycrystalline silicon (poly-Si) fin-channel tri-gate (TG)- and double-gate (DG)-type flash memories with a thin n+-poly-Si floating gate (FG) and different control-gate (CG) lengths ($L_{\text{CG}}$'s) from 76 to 256 nm have been fabricated and their electrical characteristics including statistical threshold voltage ($V_{\text{t}}$) and subthreshold slope ($S$-slope) have been comparatively investigated before and after one program/erase (P/E) cycle. It was experimentally found that better short-channel effect (SCE) immunity, a smaller $V_{\text{t}}$ variation, and a higher program speed are obtained in TG-type flash memories than in DG-type memories. The higher performance of TG-type flash memories is contributed by the additional top gate and recessed bottom silicon dioxide (SiO2) regions, which strengthen the controllability of the channel potential and increase the coupling ratio of the FG to the CG. Therefore, the developed poly-Si fin-channel TG structure is expected to be very useful for the fabrication of high-density and low-cost flash memories.

The floating-gate (FG)-type metal--oxide--semiconductor (MOS) capacitors with planar (planar-MOS) and three-dimensional (3D) nanosize triangular cross-sectional tunnel areas (3D-MOS) have successfully been fabricated by introducing rapid thermal oxidation (RTO) and postdeposition annealing (PDA), and their electrical characteristics between the control gate (CG) and FG have been systematically compared. It was experimentally found in both planar- and 3D-MOS capacitors that the uniform and higher breakdown voltages are obtained by introducing RTO owing to the high-quality thermal oxide formation on the surface and etched edge regions of the n+polycrystalline silicon (poly-Si) FG, and the leakage current is highly suppressed after PDA owing to the improved quality of the tetraethylorthosilicate (TEOS) silicon dioxide (SiO2) between CG and FG. Moreover, a lower breakdown voltage between CG and FG was obtained in the fabricated 3D-MOS capacitors as compared with that of planar-MOS capacitors thanks to the enhanced local electric field at the tips of triangular tunnel areas. The developed nanosize triangular cross-sectional tunnel area is useful for the fabrication of low operating voltage flash memories.

The crystal-Si and poly-Si fin-channel flash memories with a thin n+-poly-Si floating-gate (FG) layer have successfully been fabricated, and their electrical characteristics have systematically been investigated. It was experimentally found that the better short-channel effect (SCE) immunity, the smaller threshold voltage (Vt) variations and a higher program speed are obtained in the crystal-Si fin-channel tri-gate (TG)-type flash memories than in the double-gate (DG)-type ones. It was also confirmed that split-gate crystal-Si fin-channel flash memories show highly suppressed over-erase as compared to that in stack-gate memories. Moreover, it was found that Vt variation in the poly-Si fin-channel flash memories after a program/erase (P/E) cycle became comparable to that in the crystal-Si fin-channel memories. The measured source-drain breakdown voltage (BVDS) was higher than 3.2 V even the gate length (Lg) was down to 76 nm. The developed technology is very useful for the fabrication of scaled NOR-type flash memory.

Floating-gate (FG)-type fin-channel double-gate (DG) and tri-gate (TG) flash memories with different control-gate (CG) lengths ($L_{\text{CG}}$) from 76 to 256 nm have successfully been fabricated by using (110)-oriented silicon on insulator (SOI) wafers, and their electrical characteristics have been comparatively investigated. It was experimentally found that better short channel effect (SCE) immunity, smaller threshold voltage ($V_{\text{t}}$) variations, and a higher program speed are obtained in the TG-type flash memories than in the DG-type memories. The higher performance of the TG-type flash memory is partly due to the additional top gate and recessed buried oxide (BOX) region, which strengthen the controllability of the channel potential and increase the coupling ratio of the FG to CG. Moreover, it was also found that the measured source--drain (SD) breakdown voltage ($\mathit{BV}_{\text{DS}}$) is higher than 3.2 V even when $L_{\text{CG}}$ was reduced to 76 nm. Therefore, the developed fin-channel TG structure is expected to be very useful for the fabrication of scaled NOR-type flash memory.

This paper introduces a flex-pass-gate SRAM (Flex-PG SRAM), which is a FinFET-based SRAM to enhance both the read and write margins independently. The flip-flop in the Flex-PG SRAM consists of usual FinFETs, while the pass gates consist of double-"independent"-gate FinFETs, i.e., "four-terminal"- (4T-) FinFETs. By optimizing the current drivability in the 4T-FinFET pass gates according to operational conditions of read and write, both the read and write margins are enhanced. TCAD simulations revealed that the Flex-PG SRAM increases the read margin by 71 mV without the cell size penalty and decrease in the write margin, even when its 6s tolerance is ensured. Also, a fabricated device proved its feasibility.

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-Ge0.88Sn0.12n-MOSFETs, with an on/off current ratio one order of magnitude higher than for conventional rapid thermal annealing processing.

We apply a surface thermal fluctuation spectroscopy technique to investigate the liquid nature of ionic liquid (IL) thin films and micro-droplets. While the spectrum for bulk IL was well explained by a simple Newtonian fluid model, a significant contribution of viscoelasticity was suggested for the vacuum-deposited thin films and micro-droplets. For a sample of IL micro-droplets with statistical distributions of their size and thickness, the scanning surface fluctuation spectroscopy was demonstrated to spatially map out the thickness and viscoelasticity values for effectively investigating the correlation between them, successfully reproducing a typical surface morphology of the sample as well.

The conjunctival epithelium, which covers the sclera (the white of the eye) and lines the inside of the eyelids, is essential for mucin secretion and the establishment of a healthy tear film. Here, we describe human conjunctival development in a self-formed ectodermal autonomous multi-zone (SEAM) of cells that were derived from human-induced pluripotent stem cells (hiPSCs) and mimic whole-eye development. Our data indicate that epidermal growth factor (EGF) drives the generation of cells with a conjunctival epithelial lineage. We also show that individual conjunctival cells can be sorted and reconstituted by cultivation into a functional conjunctival epithelium that includes mucin-producing goblet cells. Keratinocyte growth factor (KGF), moreover, is necessary for the maturation of hiPSC-derived conjunctival epithelium—particularly the goblet cells—indicating key complementary roles of EGF and KGF in directing the differentiation and maturation, respectively, of the human conjunctival epithelium.

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.

Atlantoaxial rotatory fixation (AARF) resulting from drug-induced cervical dystonia (DICD) represents an extremely rare complication of antipsychotic treatment, requiring a comprehensive assessment of pharmacologic therapy and timely radiologic workup. We report a chronic case of Fielding type I, Pang type I AARF secondary to schizophrenia treatment in a 16-year-old girl, along with a review of the literature on the management challenges posed in this condition. In this scenario, torticollis may just represent the tip of the iceberg, and only an effective multidisciplinary approach increases the chances of satisfactory correction with closed reduction, hence avoiding the burden of more invasive treatment options.

In this work, we measured $1/f$ noise of independent-double-gate- (IDG-) fin-type FET (FinFET) which has two independent gates. Flicker noise of common-double-gate- (CDG-) mode which both gates are applied with the same voltage and IDG-mode that has one gate voltage grounded and the other gate voltage applied with arbitrary voltage, and both result were compared with the same drain current ($I_{\text{d}}$). First, we measured relationship between characteristic of the normalized $1/f$ noise by $I_{\text{d}}$ ($S_{I_{\text{d}}}/I_{\text{d}}^{2}$) and characteristic of $I_{\text{d}}$. Both the $S_{I_{\text{d}}}/I_{\text{d}}^{2}$ of IDG- and CDG-modes show nearly equal values and tendency. Next, this work also shows the relationship between $1/f$ noise and vertical electric field ($E_{\bot}$) of surface of gate oxide film. As a result we could not definitely see a large margin of $1/f$ noise between CDG- and IDG-modes from $E_{\bot}$. This work also discovered that $1/f$ noise was greatly influenced by $I_{\text{d}}$ density.

The GTPase-activating protein Tagap enables thymocytes to properly migrate within the thymus to undergo selection.

We investigated the impacts of plasma-induced damage due to UV light irradiation during etching on Ge fin fabrication and the device performance of Ge fin field-effect transistors (Ge FinFETs). UV light irradiation during etching affected the shape of the Ge fin and the surface roughness of the Ge fin sidewall. A vertical and smooth Ge fin could be fabricated by neutral beam etching without UV light irradiation. The performances of Ge FinFETs fabricated by neutral beam etching were markedly improved as compared to those of Ge FinFETs fabricated by inductively coupled plasma etching, in which the UV light has an impact.

Atomic layer deposition (ALD) of SiO2by using a tetraethoxysilane (TEOS) or a bis(ethylmethylamino)silane (BEMAS) have been studied for the side-wall spacer formation of the fin field effect transistor (FinFET). The ALD-SiO2can be deposited conformally at 50 °C for the TEOS and at 250 °C for the BEMAS precursor. As a result, FinFETs with a 25-nm-long extension of the source/drain using the ALD grown SiO2sidewall spacer have been successfully fabricated. The performance of the FinFET has been successfully improved by reduction of the parasitic resistance.

We have comparatively investigated the electrical characteristics including threshold voltage ($V_{\text{th}}$) variability and mobility by fabricating n+-polycrystalline silicon (poly-Si) gate and physical-vapor-deposited (PVD) titanium nitride (TiN) gate fin-type double-gate metal--oxide--semiconductor field-effect transistors (FinFETs), and demonstrated 20-nm-thick PVD-TiN gate FinFETs with a symmetrical $V_{\text{th}}$. It is experimentally found that the gate stack of a 20-nm-thick PVD-TiN layer capped with a 100-nm-thick n+-poly-Si layer is very effective for setting a symmetrical $V_{\text{th}}$ for undoped FinFETs keeping almost the same $V_{\text{th}}$ variability and mobility as those in the case of the n+-poly-Si gate only. On the other hand, mobility degradation was observed in the case of pure 50-nm-thick PVD-TiN gates. These results indicate that mobility degradation probably caused by the thick metal gate induced mechanical stress can be effectively suppressed by reducing the PVD-TiN thickness to 20 nm or less.

The impact of work function variation (WFV) in a metal gate (MG) electrode on low-frequency noise (LFN) is revealed for fin field-effect transistors (FinFETs). The LFN level is compared between the FinFETs having polycrystalline TiN and amorphous TaSiN MGs. The amorphous TaSiN MG exhibits a marked suppression of flicker noise in comparison with the TiN MG. The difference in the LFN level is correlated with the threshold voltage variability reflecting the WFV of the MG. By modeling the WFV of the TiN MG in the FinFET structure by three-dimensional device simulation, we clearly reveal the mechanism of the LFN increase by the WFV.

Floating-gate (FG)-type tri-gate flash memories with an improved inter-poly dielectric (IPD) layer have been successfully fabricated by introducing a newly developed rapid thermal oxidation (RTO) process, and their NOR-mode operation including threshold voltage ($V_{\text{t}}$) variations before and after one program/erase (P/E) cycle have been systematically investigated. It was experimentally confirmed that the gate breakdown voltage (BV\text{g) is greatly increased from 12 to 19 V by introducing the RTO process thanks to the high quality and thin thermal silicon dioxide (SiO2) formation on the FG surface and etched edge regions, which effectively blocks the leakage pass of the IPD layer. A source--drain (SD) breakdown voltage (BV\text{DS) as high as 4.5 V was obtained even when the gate length ($L_{\text{g}}$) was as small as 117 nm. It was also experimentally confirmed that the memory window increases with increasing gate voltage ($V_{\text{g}}$) in NOR-mode programming thanks to the increased efficiency of channel hot electron (CHE) injection. The developed tri-gate flash memory with improved IPD layer is useful for the further scaling of NOR-type flash memory.

In this study, we successfully introduced an atomic-layer-deposited (ALD) titanium nitride (TiN) gate grown with a tetrakis(dimethylamino)titanium (TDMAT) precursor into fin-type metal--oxide--semiconductor field-effect transistor (FinFET) fabrication for the first time, and comparatively investigated the electrical characteristics, including mobility and threshold voltage ($V_{\text{th}}$) variation, of the fabricated ALD and physical-vapor-deposited (PVD)-TiN gate FinFETs. The ALD-TiN gate FinFETs showed superior conformality to the PVD-TiN gate FinFETs. The electron mobilities of the ALD- and PVD-TiN gate FinFETs were comparable in the small $L_{\text{g}}$ region. It was also confirmed that the ALD-TiN gate FinFETs showed a smaller $V_{\text{th}}$ variation than the PVD-TiN gate FinFETs.

The nanoscale wet etching of physical-vapor-deposited (PVD) titanium nitride (TiN) and its application to sub-30-nm-gate-length fin-type double-gate metal--oxide--semiconductor field-effect transistor (FinFET) fabrication are systematically investigated. It is experimentally found that PVD-TiN side-etching depth can be controlled to be one-half of PVD-TiN thickness with precise time control using an $\text{ammonium hydroxide (NH$_{4}$OH)}: \text{hydrogen peroxide (H$_{2}$O$_{2}$)}: \text{deionized water (H$_{2}$O)}= 1 : 2 : 5$ solution at 60 \mbox{\circC}. Using the developed nanoscale PVD-TiN wet etching technique, sub-30-nm-physical-gate-length FinFETs, 100-nm-tall fin-channel complementary MOS (CMOS) inverters and static random access memory (SRAM) half-cells have successfully been fabricated and demonstrated. These experimental results indicate that the developed nanoscale PVD-TiN wet etching technique is very useful for tall fin-channel CMOS fabrication.

In this paper, we describe the superiority of the titanium nitride (TiN) film formed by atomic layer deposition (ALD) using a tetrakis(dimethylamino)titanium (TDMAT) precursor for metal-gate electrodes of planar metal--oxide--semiconductor field-effect transistors (MOSFETs). It was demonstrated that the resistivity of the ALD TiN was significantly reduced by NH3post deposition annealing (PDA). The electrical characteristics of the ALD-TiN-gate MOS capacitors and planar MOSFETs were evaluated and compared with those of the physical-vapor-deposited (PVD) TiN. The performance of the ALD-TiN-gate cases was confirmed to be superior to that of the PVD-TiN-gate cases, which was explained by the lower interface trap density ($D_{\text{it}}$) of the ALD TiN/SiO2gate stack.

The low-energy tilted ion implantation (I/I) for fin-type double-gate metal--oxide--semiconductor field-effect transistor (FinFET) source--drain (SD) extension doping is systematically investigated experimentally by fabricating a series of n+-polycrystalline silicon (poly-Si) gate n-channel FinFETs under different I/I conditions. The on-state current ($I_{\text{ON}}$) versus off-state current ($I_{\text{OFF}}$) and the SD parasitic resistance ($R_{\text{p}}$) are used for benchmarking the performance of the fabricated devices to investigate the optimal extension I/I conditions, including dose ($D$) and tilted angle ($\theta$), at a fixed low energy of 5 keV. It is experimentally found that the best extension I/I conditions are $D = 4\times 10^{14}$ cm-2and $\theta = 60$\mbox{\circ}. With further increasing $D$, the device performance deteriorates owing to the incomplete recrystallization of amorphous regions in the thin extension regions. In the case of $\theta = 0$\mbox{\circ}, marked increment and fluctuations in $R_{\text{p}}$ are observed because the implant atoms scatter out randomly from each extension region. The $R_{\text{p}}$ value of the FinFETs fabricated under the above best I/I conditions is comparable to that of devices fabricated by the solid-phase diffusion of phosphors from phosphosilicate glass (PSG). This indicates that the extension I/I conditions of $D = 4\times 10^{14}$ cm-2and $\theta = 60$\mbox{\circ} are almost optimal and is very effective for high-performance FinFET fabrication.

We propose a flexible-pass-gate (Flex-PG) fin-type field effect transistor (FinFET) static random access memory (SRAM) cell to enhance both read and write noise margins. The flip-flop in the Flex-PG SRAM cell consists of usual common-gated FinFETs while its pass gates consist of threshold voltage (Vth)-controllable four-terminal (4T) FinFETs with independent double-gates. We experimentally demonstrate that the proposed Flex-PG SRAM increases both read and write margins by controlling the Vthof the pass gates.