Source/Drain Patterning FinFETs as Solution for Physical Area Scaling Toward 5-nm Node

A novel and feasible process scheme to downsize the source/drain (S/D) epitaxy of 5-nm node bulk fin-shaped field-effect transistors (FinFETs) were introduced by using fully-calibrated TCAD for the first time. The S/D epitaxy formed by selective epitaxial growth was diamond-shaped and occupied a large proportion of the device size irrespective of the active channel area. However, this problem was solved by patterning the low-k regions prior to S/D formation by preventing the lateral overgrowth of S/D epitaxy; the so-called S/D patterning (SDP). Its smaller S/D epitaxy decreased the average longitudinal channel stresses and drive currents for NFETs. However, the small diffusions of the boron dopants into the channel regions improved the short-channel effects and alleviated the drive current reduction for PFETs. Gate capacitances decreased greatly by reducing outer-fringing capacitances between the metal-gate stack and S/D regions. Through SPICE simulation based on the virtual source model, operation frequencies and dynamic powers of 15-stage ring oscillators were studied. SDP FinFETs have better circuit performances than the conventional and bottom oxide bulk FinFETs along with smaller active areas, promising for further area scaling through simple and reliable S/D process.11Ysciescopu

Demonstration of TiO2 based ultra high-k (k=30) MIS capacitor and its electrical properties

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Defect Curing Effects on High-k Gate Stack (Al/Al2O3/Si-sub) by Using H2 Plasma Treatment and Rapid Thermal Anneal

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Interface trap curing effects on high-k gate stack (Al/Al2O3/Si-sub) by rapid thermal anneal (RTA)

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Demonstration of TiO2 Based Ultra High-k (k = 30) Metal-Insulator–Semiconductor Capacitor and Its Electrical Properties

In this paper, we investigated TiO2 as gate dielectric to achieve the large dielectric constant. The ultra high-k value over 30 was obtained by Capacitance–Voltage measurement of Al/Ti/TiO2/Si Metal-Insulator–Semiconductor (MIS) capacitor. Among as deposited, rapid thermal annealing (RTA) at 750 °C and 1000 °C, the RTA at 750 °C showed the lowest gate leakage current. It implies that TiO2 has optimum RTA temperature having the lowest leakage current. When TiO2 is annealed at 750 °C, the phase of TiO2 changes to anatase and interfacial layer between TiOx and Si was formed. While TiO2 is annealed at 1000 °C, the phase of TiO2 changes to rutile and diffusion of silicon atoms was clearly observed and it causes the silicide formation. Based on measurement data, we proposed the energy band diagram of Al/TiO2/Si MIS capacitors. This diagram shows that the energy band gap of RTA at 750 °C is expanded while that of RTA at 1000 °C is contracted. In addition, TiO2 with RTA at 550 °C was tested to confirm leakage current and it shows lower leakage current than RTA at 750 °C as we expected. This result confirmed that optimum RTA temperature of TiO2 would exist under 750 °C.11Nsci

Electrical and Dielectric Properties of TiO2 Based MIS Capacitor

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H₂ Plasma and PMA Effects on PEALD-Al₂O₃ Films with Different O₂ Plasma Exposure Times for CIS Passivation Layers

In this study, the electrical properties of Al2O3 film were analyzed and optimized to improve the properties of the passivation layer of CMOS image sensors (CISs). During Al2O3 deposition processing, the O2 plasma exposure time was adjusted, and H2 plasma treatment as well as post-metallization annealing (PMA) were performed as posttreatments. The flat-band voltage (Vfb) was significantly shifted (ΔVfb = 2.54 V) in the case of the Al2O3 film with a shorter O2 plasma exposure time; however, with a longer O2 plasma exposure time, Vfb was slightly shifted (ΔVfb = 0.61 V) owing to the reduction in the carbon impurity content. Additionally, the as-deposited Al2O3 sample with a shorter O2 plasma exposure time had a larger number of interface traps (interface trap density, Dit = 8.98 × 1013 eV−1·cm−2). However, Dit was reduced to 1.12 × 1012 eV−1·cm−2 by increasing the O2 plasma exposure time and further reduced after PMA. Consequently, we fabricated an Al2O3 film suitable for application as a CIS passivation layer with a reduced number of interface traps. However, the Al2O3 film with increased O2 plasma exposure time deteriorated owing to plasma damage after H2 plasma treatment, which is a method of reducing carbon impurity content. This deterioration was validated using the C–V hump and breakdown characteristics

Developmental Transcriptome Analysis of Red-Spotted Apollo Butterfly, Parnassius bremeri

Parnassius bremeri (P. bremeri), a member of the genus Snow Apollo in the swallowtail family (Papilionidae), is a high alpine butterfly that lives in Russia, Korea, and China. It is an endangered wildlife (Class I) in South Korea and is a globally endangered species. The lack of transcriptomic and genomic resources of P. bremeri significantly hinders the study of its population genetics and conservation. The detailed information of the developmental stage-specific gene expression patterns of P. bremeri is of great demand for its conservation. However, the molecular mechanism underlying the metamorphic development of P. bremeri is still unknown. In the present study, the differentially expressed genes (DEGs) across the metamorphic developmental stages were compared using high-throughput transcriptome sequencing. We identified a total of 72,161 DEGs from eight comparisons. GO enrichment analysis showed that a range of DEGs were responsible for cuticle development and the melanin biosynthetic pathway during larval development. Pathway analysis suggested that the signaling pathways, such as the Wnt signaling pathway, hedgehog signaling pathway and Notch signaling pathway, are regulated during the developmental stages of P. bremeri. Furthermore, sensory receptors were also activated, especially during the larval to adult transition stage. Collectively, the results of this study provide a preliminary foundation and understanding of the molecular mechanism in their transcriptomes for further research on the metamorphic development of P. bremeri

FBXL17/spastin axis as a novel therapeutic target of hereditary spastic paraplegia

Abstract Background Spastin significantly influences microtubule regulation in neurons and is implicated in the pathogenesis of hereditary spastic paraplegia (HSP). However, post-translational regulation of the spastin protein remains nebulous. The association between E3 ubiquitin ligase and spastin provides a potential therapeutic strategy. Results As evidenced by protein chip analysis, FBXL17 inversely correlated with SPAST-M1 at the protein level in vitro and, also in vivo during embryonic developmental stage. SPAST-M1 protein interacted with FBXL17 specifically via the BTB domain at the N-terminus of SPAST-M1. The SCFFBXL17 E3 ubiquitin ligase complex degraded SPAST-M1 protein in the nuclear fraction in a proteasome-dependent manner. SPAST phosphorylation occurred only in the cytoplasmic fraction by CK2 and was involved in poly-ubiquitination. Inhibition of SCFFBXL17 E3 ubiquitin ligase by small chemical and FBXL17 shRNA decreased proteasome-dependent degradation of SPAST-M1 and induced axonal extension. The SPAST Y52C mutant, harboring abnormality in BTB domain could not interact with FBXL17, thereby escaping protein regulation by the SCFFBXL17 E3 ubiquitin ligase complex, resulting in loss of functionality with aberrant quantity. Although this mutant showed shortening of axonal outgrowth, low rate proliferation, and poor differentiation capacity in a 3D model, this phenotype was rescued by inhibiting SCFFBXL17 E3 ubiquitin ligase. Conclusions We discovered that a novel pathway, FBXL17-SPAST was involved in pathogenicity of HSP by the loss of function and the quantitative regulation. This result suggested that targeting FBXL17 could provide new insight into HSP therapeutics