Study of the Effects of the Antisite Related Defects in Silicon Dioxide of Metal-Oxide-Semiconductor Structure on the Gate Leakage Current

Mao, Ling-Feng,Wang, Zi-Ou,Xu, Ming-Zhen,Tan, Chang-Hua The Institute of Electronics and Information Engin 2008 Journal of semiconductor technology and science Vol.8 No.2

The effects of the antisite related defects on the electronic structure of silica and the gate leakage current have been investigated using first-principles calculations. Energy levels related to the antisite defects in silicon dioxide have been introduced into the bandgap, which are nearly 2.0 eV from the top of the valence band. Combining with the electronic structures calculated from first-principles simulations, tunneling currents through the silica layer with antisite defects have been calculated. The tunneling current calculations show that the hole tunneling currents assisted by the antisite defects will be dominant at low oxide field whereas the electron direct tunneling current will be dominant at high oxide field. With increased thickness of the defect layer, the threshold point where the hole tunneling current assisted by antisite defects in silica is equal to the electron direct tunneling current extends to higher oxide field.

Genetic Diversity and Geographical Differentiation of Desmodium triflorum (L.) DC. in South China Revealed by AFLP Markers

Mao-feng Yue,Ren-chao Zhou,Ye-lin Huang,Guo-rong Xin,Su-hua Shi,Li Feng 한국식물학회 2010 Journal of Plant Biology Vol.53 No.2

High levels of genetic variation enable species to adapt to changing environments and provide plant breeders with the raw materials necessary for artificial selection. In the present study, six AFLP primer pairs were used to assess the genetic diversity of Desmodium triflorum (L.)DC. from 12 populations in South China. A high percentage of polymorphic loci (P=76.16%) and high total gene diversity (HT=0.310) were found, indicating that the genetic diversity of D. triflorum is high at the species level. Genetic diversity was also relatively high at the population level (P=55.85%, He=0.230). The coefficient of gene differentiation among populations (GST) was 0.255, indicating that while most genetic diversity resided within populations, there was also considerable differentiation among populations. AMOVA also indicated 24.29% of the total variation to be partitioned among populations (ΦST=0.243). UPGMA clustering analysis based on genetic distances showed that the 12 populations could be separated into three subgroups: an eastern, a western, and a central-southern subgroup. However, a Mantel test revealed no significant correlation (r=0.286, p=0.983)between the geographical distances and genetic distances separating these populations; mountain barriers to gene flow and human disturbance may have confounded these correlations. The present study has provided some fundamental genetic data that will be of use in the exploitation of D. triflorum.

Effects of Channel Electron In-Plane Velocity on the Capacitance-Voltage Curve of MOS Devices

Ling-Feng Mao 한국전자통신연구원 2010 ETRI Journal Vol.32 No.1

The coupling between the transverse and longitudinal components of the channel electron motion in NMOS devices leads to a reduction in the barrier height. Therefore, this study theoretically investigates the effects of the in-plane velocity of channel electrons on the capacitance-voltage characteristics of nano NMOS devices under inversion bias. Numerical calculation via a self-consistent solution to the coupled Schrödinger equation and Poisson equation is used in the investigation. The results demonstrate that such a coupling largely affects capacitance-voltage characteristic when the in-plane velocity of channel electrons is high. The ballistic transport ensures a high in-plane momentum. It suggests that such a coupling should be considered in the quantum capacitance-voltage modeling in ballistic transport devices.

Incidence of Thymoma in Myasthenia Gravis: A Systematic Review

Zhi-Feng Mao,Xue-An Mo,Yong-Rong Lai,Maree L. Hackett 대한신경과학회 2012 Journal of Clinical Neurology Vol.8 No.3

Background and Purpose Myasthenia gravis (MG) is usually comorbid with thymoma. More accurate estimates of the incidence thymoma in MG will help inform patients and their physicians, facilitate health policy discussions, provide etiologic clues, and optimize the management of MG. Methods We conducted a systematic review search of relevant English-language studies published between 1960 and 2012 using MEDLINE and Embase. We identified additional studies by reviewing the bibliographies of the retrieved articles and hand searched the main neurology journals. Only incidence studies and case series of unselected MG patients in which information about thymoma were included. Results Out of 2206 potentially relevant studies, 49 met the inclusion criteria. Although there was a considerable degree of heterogeneity, the pooled estimate of the incidence of thymoma in MG was 21% (95% confidence interval, 20-22%). The pooled incidence was significantly higher for surgery-based studies than for population- and hospital-based studies. A large proportion of the reported thymomas were noninvasive. Furthermore, thymoma appears to occur significantly more frequently among male MG patients and those older than 40 years at the onset of MG. Conclusions Thymoma is common in MG patients, but appears to be found more often in male MG patients and those older than 40 years at the onset of MG. Further research is needed to expand our understanding of these association conditions

Impact of Energy Relaxation of Channel Electrons on Drain- Induced Barrier Lowering in Nano-Scale Si-Based MOSFETs

Ling-Feng Mao 한국전자통신연구원 2017 ETRI Journal Vol.39 No.2

Drain-induced barrier lowering (DIBL) is one of the main parameters employed to indicate the short-channel effect for nano metal-oxide semiconductor field-effect transistors (MOSFETs). We propose a new physical model of the DIBL effect under two-dimensional approximations based on the energy-conservation equation for channel electrons in FETs, which is different from the former field-penetration model. The DIBL is caused by lowering of the effective potential barrier height seen by the channel electrons because a lateral channel electric field results in an increase in the average kinetic energy of the channel electrons. The channel length, temperature, and doping concentration-dependent DIBL effects predicted by the proposed physical model agree well with the experimental data and simulation results reported in Nature and other journals.

Study of the Effects of the Antisite Related Defects in Silicon Dioxide of Metal-Oxide-Semiconductor Structure on the Gate Leakage Current

Ling-Feng Mao,Zi-Ou Wang,Ming-Zhen Xu,Chang-Hua Tan 대한전자공학회 2008 Journal of semiconductor technology and science Vol.8 No.2

The effects of the antisite related defects on the electronic structure of silica and the gate leakage current have been investigated using first-principles calculations. Energy levels related to the antisite defects in silicon dioxide have been introduced into the bandgap, which are nearly 2.0 eV from the top of the valence band. Combining with the electronic structures calculated from first-principles simulations, tunneling currents through the silica layer with antisite defects have been calculated. The tunneling current calculations show that the hole tunneling currents assisted by the antisite defects will be dominant at low oxide field whereas the electron direct tunneling current will be dominant at high oxide field. With increased thickness of the defect layer, the threshold point where the hole tunneling current assisted by antisite defects in silica is equal to the electron direct tunneling current extends to higher oxide field.

IL-33 promotes IL-10 production in macrophages: a role for IL-33 in macrophage foam cell formation

Hai-Feng Zhang,Mao-Xiong Wu,Yong-Qing Lin,Shuang-Lun Xie,Tu-Cheng Huang,Pin-Ming Liu,Ru-Qiong Nie,Qin-Qi Meng,Nian-Sang Luo,Yang-Xin Chen,Jing-Feng Wang 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

We evaluated the role of IL-10- in IL-33-mediated cholesterol reduction in macrophage-derived foam cells (MFCs) and the mechanism by which IL-33 upregulates IL-10. Serum IL-33 and IL-10 levels in coronary artery disease patients were measured. The effects of IL-33 on intra-MFC cholesterol level, IL-10, ABCA1 and CD36 expression, ERK 1/2, Sp1, STAT3 and STAT4 activation, and IL-10 promoter activity were determined. Core sequences were identified using bioinformatic analysis and sitespecific mutagenesis. The serum IL-33 levels positively correlated with those of IL-10. IL-33 decreased cellular cholesterol level and upregulated IL-10 and ABCA1 but had no effect on CD36 expression. siRNA-IL-10 partially abolished cellular cholesterol reduction and ABCA1 elevation by IL-33 but did not reverse the decreased CD36 levels. IL-33 increased IL-10 mRNA production but had little effect on its stability. IL-33 induced ERK 1/2 phosphorylation and increased the luciferase expression driven by the IL-10 promoter, with the highest extent within the − 2000 to − 1752 bp segment of the 5′-flank of the transcription start site; these effects were counteracted by U0126. IL-33 activated Sp1, STAT3 and STAT4, but only the STAT3 binding site was predicted in the above segment. Site-directed mutagenesis of the predicted STAT3-binding sites (CTGCTTCCTGGCAGCAGAA→CTGCCTGGCAGCAGAA) reduced luciferase activity, and a STAT3 inhibitor blocked the regulatory effects of IL-33 on IL-10 expression. Chromatin immunoprecipitation (CHIP) confirmed the STAT3-binding sequences within the − 1997 to − 1700 and − 1091 to − 811 bp locus regions. IL-33 increased IL-10 expression in MFCs via activating ERK 1/2 and STAT3, which subsequently promoted IL-10 transcription and thus contributed to the beneficial effects of IL-33 on MFCs.

Modeling negative and positive temperature dependence of the gate leakage current in GaN high-electron mobility transistors

Ling-Feng Mao 한국전자통신연구원 2022 ETRI Journal Vol.44 No.3

Monte Carlo simulations show that, as temperature increases, the average kinetic energy of channel electrons in a GaN transistor first decreases and then increases. According to the calculations, the relative energy change reaches 40%. This change leads to a reduced barrier height due to quantum coupling among the three-dimensional motions of channel electrons. Thus, an analysis and physical model of the gate leakage current that includes drift velocity is proposed. Numerical calculations show that the negative and positive temperature dependence of gate leakage currents decreases across the barrier as the field increases. They also demonstrate that source–drain voltage can have an effect of 1 to 2 orders of magnitude on the gate leakage current. The proposed model agrees well with the experimental results.

日本語教育における教室学習と自然習得 - 台湾の場合 -

蔡茂豊(Tsai Mao-Feng) 일본어문학회 2005 일본어문학 Vol.30 No.-

Molecular Dynamics Simulation to Investigate the Rake Angle Effects on Nanometric Cutting of Single Crystal Ni3Al

Rui-cheng Feng,Yong-nian Qi,Zong-xiao Zhu,Wen-yuan Song,Hai-yan Li,Mao-mao Wang,Zhi-yuan Rui,Feng-shou Gu 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.4

Molecular dynamics, an eff ective method to gain an insight into nanometric behaviour of materials, was employed to studythe nano-cutting behaviour of single crystal Ni 3 Al in nanometric scale. In this paper, comparisons were made for compressive/tensile stress, subsurface damage and surface roughness with three rake angles of a diamond tool. Subsurface damage waspartitioned by region and studied with work hardening in detail. A model for precise characterization of surface roughnesswas established with consideration of local surface fl uctuation. Simulation results showed that the chip thickness increasedas rake angle changed from negative to positive, and the boundary formed between tensile and compressive stress was inconsistent with the glide direction of stacking fault. Subsurface damage decreased as the increase of rake angle, and regularglide planes of stacking faults were found in front of the cutting tool. Further, the pinned dissociated 1/2 < 110 > superpartialdislocation with anti-phase boundary was demonstrated. The model was tested and characterized by implanted pits onperfect surface. Results showed that surface roughness can be well characterized, and an evident discrepancy was observedamong three rake angles, especially for 30° rake angle, which showed an distinct smooth surface compared with the others.