bluuebunny/crossref_metadata_2025 huggingface dataset:
LATERAL ANKLE SPRAIN — AN UPDATE
Authors: Nuhmani Shibli , Khan Moazzam Hussain
Published: March 2014

Ankle sprain injuries are the most common injury sustained during sporting activities. One-sixth of all sports injury loss time is from ankle sprains. Each year, an estimated 1 million people present to physicians with acute ankle injuries. Three-quarters of ankle injuries involve the lateral ligamentous complex, comprised of the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL) and the posterior talofibular ligament (PTFL). Lateral ankle sprains typically occur when the rearfoot undergoes excessive supination on an externally rotated lower leg. The diagnosis of a sprain relies on the medical history including symptoms, as well as making a differential diagnosis mainly in distinguishing it from strains or bone fractures. Despite their prevalence in society, ankle sprains still remain a difficult diagnostic and therapeutic challenge in the athlete, as well as in society in general. The high incidence of ligamentous ankle injuries requires clearly defined acute care and a broad knowledge of new methods in rehabilitation. In addition to rapid pain relief, the main objective of treatment is to quickly restore the range of motion of the ankle without any major loss of proprioception, thereby restoring full activity as soon as possible. The purpose of this article is to review the anatomy, pathomechanics, investigation, diagnosis and management of lateral ankle sprains.
COVARIANCE AND CORRELATION SWAPS FOR FINANCIAL MARKETS WITH MARKOV-MODULATED VOLATILITIES
Authors: SALVI GIOVANNI , SWISHCHUK ANATOLIY V.
Published: March 2014

In this paper, we price covariance and correlation swaps for financial markets with Markov-modulated volatilities. As an example, we consider stochastic volatility driven by a two-state continuous Markov chain. In this case, numerical examples are presented for VIX and VXN volatility indices (S&P 500 and NASDAQ-100, from January 2004 to June 2012). We also use VIX (January 2004 to June 2012) to price variance and volatility swaps for the two-state Markov-modulated volatility, and we present a numerical result in this case.
On the asymptotic behavior of generic quantum Markov semigroups
Authors: Carbone R. , Sasso E. , Umanità V.
Published: March 2014

We study ergodicity and decoherence for generic quantum Markov semigroups: in particular, we highlight the strong relationships among these properties, the convergence in law of the classical Markov process associated with the diagonal part of the semigroup, and the structure of its communication classes.
MICROCREDIT, CIVIC NETWORKS AND WOMEN'S POLITICAL INVOLVEMENT IN BANGLADESH
Authors: UDDIN MOHAMMAD JASIM
Published: March 2014

The social capital school has proposed that one of the key mechanisms for generating good democratic outcomes is participation in voluntary associations. Of late, group-based microcredit programmes are considered as effective policy instruments for generating and strengthening civic networks of the community. However, on the micro-level we do not know enough about how membership in microcredit programmes promotes civic engagement, nurtures democratic learning process and makes their members more cooperative. In this paper I investigate whether microcredit providing NGOs have run through and nurtured democratic practices at the local level and whether they mobilize citizens politically and promote leadership among the women. The results indicate that microcredit organizations in the area that I studied failed to promote women's political capabilities or civic engagement since these organizations mainly concentrate on the services of credit distribution and installments collection, and have deviated or shifted away from community mobilization.
「建構有效家庭服務： 綜合家庭服務中心模式實施情況檢討」的評論和反思
Authors: 游 達裕 , 張 超雄 , 朱 志強
Published: March 2014

2008年，香港大學顧問團受社會福利署的委託而進行綜合家庭服務中心服務檢討，於2010年完成研究並發表「綜合家庭服務中心服務模式實施情況檢討」報告書。

本文深入分析港大研究報告書後，發現該報告書欠缺分析過往相關文獻的討論；重複過往研究的結果，結論卻沒有進一步分析和探究；概念含混，沒有清晰的標準作評估準則；只引用社工的意見而沒有進一步分析或評論，尤其在一些重要的議題上，前後不一致；推論不合邏輯。 從這研究的資料所見，綜合家務服務中心的角色和功能不斷受到社會基層和相關持份者所修正和界定，因此我們亦應反思社會工作的政治實踐。

我們相信港大顧問團眾多學者都具備足夠能力去進行具學術水平的研究，正因為這緣故，它令我們對學者的角色和研究報告所帶來的倫理責任進行反思。
Chlorophyll Modifications and Their Spectral Extension in Oxygenic Photosynthesis
Authors: Chen Min
Published: March 2014

Chlorophylls are magnesium-tetrapyrrole molecules that play essential roles in photosynthesis. All chlorophylls have similar five-membered ring structures, with variations in the side chains and/or reduction states. Formyl group substitutions on the side chains of chlorophyll a result in the different absorption properties of chlorophyll b, chlorophyll d, and chlorophyll f. These formyl substitution derivatives exhibit different spectral shifts according to the formyl substitution position. Not only does the presence of various types of chlorophylls allow the photosynthetic organism to harvest sunlight at different wavelengths to enhance light energy input, but the pigment composition of oxygenic photosynthetic organisms also reflects the spectral properties on the surface of the Earth. Two major environmental influencing factors are light and oxygen levels, which may play central roles in the regulatory pathways leading to the different chlorophylls. I review the biochemical processes of chlorophyll biosynthesis and their regulatory mechanisms.
Energy Supply Chain Optimization of Hybrid Feedstock Processes: A Review
Authors: Elia Josephine A. , Floudas Christodoulos A.
Published: March 2014

The economic, environmental, and social performances of energy systems depend on their geographical locations and the surrounding market infrastructure for feedstocks and energy products. Strategic decisions to locate energy conversion facilities must take all upstream and downstream operations into account, prompting the development of supply chain modeling and optimization methods. This article reviews the contributions of energy supply chain studies that include heat, power, and liquid fuels production. Studies are categorized based on specific features of the mathematical model, highlighting those that address energy supply chain models with and without considerations of multiperiod decisions. Studies that incorporate uncertainties are discussed, and opportunities for future research developments are outlined.
Agent-Based Models
Authors: de Marchi Scott , Page Scott E.
Published: March 2014

Agent-based models (ABMs) provide a methodology to explore systems of interacting, adaptive, diverse, spatially situated actors. Outcomes in ABMs can be equilibrium points, equilibrium distributions, cycles, randomness, or complex patterns; these outcomes are not directly determined by assumptions but instead emerge from the interactions of actors in the model. These behaviors may range from rational and payoff-maximizing strategies to rules that mimic heuristics identified by cognitive science. Agent-based techniques can be applied in isolation to create high-fidelity models and to explore new questions using simple constructions. They can also be used as a complement to deductive techniques. Overall, ABMs offer the potential to advance social sciences and to help us better understand our complex world.
A Method of Optimizing Mosfets through Engineering Knowledge-Based Analysis and Efficient Design of Experiments for 28nm Technology Node and Beyond
Authors: Shi XueJie , Yang Siyuan Frank , Pu YueJiao , Fang Lei , Wu Hong , Pan ZiCheng , Ding Yu Kellin , Lee Byung-Hak , Zhang QingChun Jason , Tao JiaJia Jeremy , Yang Tao Allen , Yu Shaofeng
Published: March 2014

In this paper, a practice of design of experiments and data analysis for 28nm technology NMOS devices was introduced. Integrated-Optimum Optimal Design design with I-optimality method criterion was used for 5 input variables with 3 levels for each device, where total 23 runs/wafers were generated. Based on the response surface models by an excellent regression on device parametric data, both automatic maximum desirability analyses by JMP software and engineering knowledge-based analysis was were carried out. The two methods generated similar prediction and the latter one helps gaining more insight on the device optimization. The prediction was exactly reproduced in silicon experiement.
Process Optimization for 20nm Planar Pmos Device
Authors: Xie Xinyun , Zhao Jie , Ju Jianhua
Published: March 2014

In this paper, we studied metal gate and implant process for optimization 20nm planar PMOS logic device, including metal gate work function tuning and performance enhancement. The paper has checked in details the work function sensitivity to metal gate related processes and also showed the impact on PMOS device performance. If Al diffuses to PWF (PMOS work function) layer, long channel device sub-threshold voltage shifts higher and short channel device performance degrades obviously. Thick PMOS work function layer or add of Al diffuse barrier layer can avoid the issue. We also showed that PWF layer removal process (PMOS work function layer needs be removed at NMOS area) impacts on PMOS device parameters and the process window needs careful tuning. Implant optimization can obviously improve PMOS device performance with embed-SiGe source/drain.
Contact CD Uniformity and Hole Circularity Improvement in 32/28 nm Node: Effect of Substrate Properties and Chemical Material Baking Temperature
Authors: Zheng Zhe , Hao Jingan , Li Gaorong , Yang Frank , Wu Qiang , Lin Alien
Published: March 2014

Contact patterning is one of the critical steps in a state-of-the-art lithography process. One of the main challenges for developing contact patterning process in 32/28 nm technology node is to achieve better critical dimension uniformity (CDU) and smaller circularity of the contact holes. In this paper we study the CDU and pattern shape variation affected by material chemical properties and baking temperature. By employing DOE (Design of Experiment) methods, we have found that the contact holes CDU can be determined by the photoresist types and BARC (Bottom Anti-Reflective Coater) baking temperature. For one type photoresist, we have found that the circularity of contact holes falls into nearly linear relationship with the CD value, which can not be affected either by the baking temperatures of the photoresist and BARC materials or by the developing process. In addition, we have also found that contact layer defect scan results and final hole profile after etch can be altered by the sidewall angle and/or the profile of the photoresist, which is near vertical. To satisfy photoresist cross section profile sidewall angle requirement, the negative impact from the substrate films to the photoresist profile has to be studied and reduced. Finally, we will present the defect scan result for our experiments in CDU and pattern profile.
Studies of Photo Resist Profile Improvement in 28 nm Implanting Layer’s Lithography Process without BARC
Authors: Liu Yang , Hu Huayong , Liu Chang , Wu Qiang , Shi Xuelong
Published: March 2014

Implant layer patterning at 28nm node is becoming challenging , due to decreasing CD and usage of non-uniform substrates without BARC. Nevertheless a prevalent LDD loop will not introduce BARC for the concern of cost and process complication. The considerable bottom reflectivity not only causes standing wave in photo resist but also introduces slight PR footing if the substrate topography is rough. In this paper, several factors of the implant litho process which impacts the PR profile and line width roughness (LWR) are studied. Firstly we changed the mask bias and simultaneously modified the exposure dosage, which is based on our previous study and will result in better photo resist profile. Secondly we studied the PR profile dependence on temperature of post exposure baking (PEB), we tried out the best temperature setting to improve PR footing. Thirdly we slightly shifted the focus offset during exposure away from the best focus defined by process FEM results, so that the photoresist profile is improved and meanwhile maintaining a large enough depth of focus for the process.
An Investigation on OPC Model Coverage to Improve CD Uniformity
Authors: Wang Liang , Zhang Yingchun , Xu Yao , Liu Qingwei , Shi Xuelong
Published: March 2014

Model-based Optical Proximity Correction (model-based OPC) has become a necessity for state of the art IC fabrication at advanced node technology. It needs one “reliable” OPC model for successful application of model-based OPC. Namely, the reliable OPC model needs to have much wider coverage and high accuracy to characterize the physical processes that take place during the photoresist exposure and development. One of the key factors for reliability of OPC model is model coverage which depends strongly on test pattern samples for model calibration. In this paper, two sets of test structures were selected to do OPC model calibration to qualify CD uniformity of patterns in array structures at 3xnm technology node. The results show the intermediate number of features for a given pitch is necessary for wider coverage of OPC model. The model including such patterns can improve CD uniformity of array structure. One methodology to design optimal permutation and combination for test patterns is proposed.
Novel Polymeric Sulfonium Photoacid Generator and Its Application for Chemically Amplified Photoresists
Authors: Liu Juan , Wang Liyuan
Published: March 2014

The polymeric PAGs based resist systems which incorporated the PAG units into the main chain showed improved lithographic performance, such as faster photospeed and higher stability, lower outgassing, and lower LER than corresponding blend resists. In this paper, with poly (4-hydroxylstyrene) (PHS) as raw material, a new type of polymeric photoacid generators (PAGs) was synthesized with sulfonuium triflate groups bonded onto part of the benzene rings. The phenolic hydroxyl group was partly esterified to improve its solubility in common organic solvents for resists. Upon irradiation to light, the sulfonium units in the polymer effectively decomposed to generate sulfonic acid. The properties of the novel polymeric PAGs were investigated. Chemically amplified photorssists can be formed by the polymeric PAG and other film forming material containing acid labile groups.
The Mask 3D Effect on 2D Pattern Shape Fidelity, a Simulation Study
Authors: Wu Qiang , Pei Jinhua , Zheng Zhe , Zhang Wanjuan , Shi Xuelong
Published: March 2014

Mask 3D effect has been viewed as a drawback to the pattern fidelity with major characteristics in higher mask error factor (MEF), lower image contrast, or exposure latitude (EL), and reduced common depth of focus (DOF) between dense and semi-dense patterns. Recently, we found that the mask 3D scattering can also result in pattern shape variation, which can make optical proximity correction (OPC) less difficult. We use both thin mask simulation and the 3D mask simulation tools on a regular proximity test pattern of contact holes and found that the holes are usually elliptical and the degree of ellipse is primarily dependent on the relative image contrast values in the mutually orthogonal dimensions, or X and Y directions. And we found through simulation that the mask 3D scattering can reduce the imaging contrast in the relatively speaking denser dimension, which will make the contact look more round.
The Reduction of Post Contact Glue Layer Peeling Defects in Gate Last Approach
Authors: Zhang Cheng-Long , He Qi-Yang , Han Qiu-Hua , Zhang Hai-Yang , Pan Zhou-Jun , Jiang Xiao-jun
Published: March 2014

Gate last approach has started to appear in the high performance applications since 45nm technoology node. Such approach has to leverage the extra metal CMP (chemical mechanical polising) to planarize the working function metal and form the metal gate. However, it’s well known that the metal CMP itself is incapable of controlling the performance at bevel area. Even worse, coupled with the instability of CMP residua, the non-optimized litho EBR process and the side-effect of integraton scheme, this poses the challenges for peeling defect control for the sake of the potential stress mismatch, the complex film stack at boundary and the weak adhesion among different film remainings at bevel area. This works aims to come up with one overall solution to post contact glue layer peeling issue including both dielectric film peeling and metallic film peeling at wafer edge area. Besides the selection of insert point and the selectivity optimzation for bevel etch, the adjustment of substrate, litho EBR and the control range of bevel etch are also proven imperative. The final over-all solution demonstrates both kinds of peeling defects could be remarkably alleviated, thus leading to yield enhancement.
The Optimization of Metal Hard-Mask Based All-in-One Etch
Authors: Zhang Cheng-Long , Hu Minda , Zhou Junqing , Wang Dongjiang , He Qi-Yang , Zhang Hai-Yang
Published: March 2014

Metal hard-mask based all-in-one etch scheme has been extensively integrated with Cu interconnects for its significant improvement in terms of the line sidewall roughness, the reduction of ultra low-k material damage and the enhancement of lithography process window. In this paper, we investigated the trade-off relationship between electromigration (EM) and time-dependence break-down (TDDB) on one AMEC (Advanced Micro-fabrication Equipment Company) test vehicle. This etcher features the special switchable rf-power at bottom electrode. Results indicate the dynamic ESC (electrostatic chuck) is imperative to meet the quite different temperature demands between via etch and trench etch step, thus reducing the via encroachment on metal hard-mask while no metallic residue is detected at trench bottom. Meanwhile, the tunable edge ring coupled with the optimization of trench etch gases are also critical to deliver the on-target Rc and reliability performance. In brief, we successfully demonstrated the partial SAV (self-aligned via) could deliver the on-target WAT and reliability performance on AD-RIE.
The Critical Role of the Plasma-Based Post Litho Treatment
Authors: Han Qiu-Hua , Meng Xiao-Ying , Huang Jing-Yong , Jiang Xiao-Jun , He Qi-Yang , Wang Dong-Jiang , Huang Rui-Xuan , Hu Min-Da , Zhang Hai-Yang
Published: March 2014

Since CMOS technology moved to 28nm node and beyond, ArF immersion lithography process already reached its limitation from the point of view of line width roughness (LWR) and photo resist (PR) profile control. The majority of this work focused on the modification of PR surface morphology at poly-gate LWR, poly-gate line-cut, contact etch and metal hard-mask open process by means of plasma-based post litho treatment (PPLT). Results indicate the 15% LWR improvement has been achieved with the optimized PPLT for poly-si gate, PPLT is also a must-have step at poly-gate line-cut process to alleviate the impact of poor PR sidewall roughness and marginal OPC window, and ensure the on-target head-to-head space without any bridge issue. OUL step is the key step to deliver the much smaller head-to-head space. The capability of different etching gases at optical under-layer (OUL) are compared in terms of head-to-head space and bridge defect. Besides, we also demonstrated PPLT is effective to greatly improve the PR footing profile/scumming induced DVC (Dark voltage contrast) and high Rc issue at contact etch. Briefly, PPLT can remarkably extend the lithography process window and demonstrate the robust overall fabrication performance.
Si Etching for TSV Formation
Authors: Wang Zhun , Jiang F , Yu D Q , Zhang W Q
Published: March 2014

Through silicon via (TSV) technology is being considered as a promising technology in three-dimensional packaging, enabling massive and short interconnections between stacked chips, increasing performance and data bandwidth, and reducing signal delay and the power consumption. Currently, TSVs with diameters ranging from one hundred to ten micrometers are mainly fabricated by deep reactive ion etching (DRIE) technology. The Bosch process is the most widely utilized DRIE process for producing high-aspect ratio TSVs. The primary steps in the Bosch process are silicon isotropic etching and wall passivation in sequential cycles. SF6 is used as the main etching gas for the high density of F+ radicals; C4F8 is used in wall passivation as it polymerizes to deposits on walls to form an etch barrier that is sufficiently impervious to side scattered F+ ions but not to direct ions at the bottom of the via. Wall scalloping occurs primarily near the top of the via where scattered ions have wide trajectories and less at greater depths where ion trajectories are more restricted. Controlling the scallop is key good insulation and metal coverage. In this study, TSVs with scallops smaller than 100nm was obtained by adjusting the flow ratio of SF6 to C4F8 and the cycle time ratio between SF6 and C4F8. Unfortunately this combination leads to the formation of silicon grass at the bottom of the TSV. The addition of O2 during the SF6 etch cycle was found to eliminate the occurrence of Si grass. Finally, TSVs with low scallop were consistently obtained without Si grass by using SF6/O2 during the etch cycle and C4F8 during the passivation cycle.
Electrical Characteristics of n-Type Diamond Contacts with Ti, Ni, NiSi2 and Ni3P Electrodes
Authors: Takemasa Atsushi , Kakushima Kuniyuki , Sugii Nobuyuki , Nishiyama Akira , Tsutsui Kazuo , Natori Kenji , Iwai Hiroshi
Published: March 2014

A semiconductor diamond draws an attention as a future semiconductor material for power devices. The main issue of the diamond is high resistance of the metal/n-diamond contact. It was reported that this is caused by the Fermi level pinning which forms a Schottky barrier of ~4.3 eV at the contact. In this research, J-V characteristics of four types of contacts using metal electrodes, Ti, Ni, NiSi2, and Ni3P and n-diamond with phosphorus concentration of 5 x 1019 cm-3 were investigated. It was observed that the contact with the Ni3P electrode flowed larger current than others at low bias voltages. This improvement might be caused by the phosphorus diffusion into the diamond substrate. It was shown that a metal electrode containing impurities has a possibility to decrease the contact resistance with n-diamond.
Investigation of Poly Film Application in Advanced MOSFET Technology
Authors: He You Feng , Zhu Haifeng , Jin Lan , He Yonggen , Wu Jingang
Published: March 2014

Un-doped poly process becomes more critical with CMOS scaling down as gate electrode in advanced Poly/SiON process and dummy poly in HK/MG technology. The poly grain size and roughness impact the device mis-match between different transistors like NMOS off current fluctuation and it plays as dummy poly role in HK/MG technology. It is necessary to investigate the poly grain size after deposition and thermal process as it will change the poly grain structure. In this paper, top view Scanning Electrical Microscope (SEM), X-ray Diffraction (XRD),Atomic Force Microscopy (AFM) and Transmission Electron Microscope (TEM) are used to characterize the poly grain size, crystalline fraction, surface roughness and poly structure. It is find that the poly grain becomes larger after thermal, especially spike anneal. A smaller grain size of undoped poly with lower roughness was achieved by process tuning of temperature, pressure, gas flow etc which was implemented in device wafer and get improved performance.
Optimization of Barrier Slurry and Process for Advanced technology Node
Authors: Song Kerry , Cao Christian , Shi Fengjun , Xu Yanting , Yang Shunbin , Wei Zhongya , Guo Shunhua
Published: March 2014

As the technology node is advanced to 28nm and below, several new materials are introduced such as ultra low-k dielectric and metal hard mask. This presents critical chalenges to Cu-CMP in terms of k-shift, poor within-die uniformity and deteriorated breakdown voltage. Such issues must be resolved before moving to mass production. This paper presents a practical solution with improved barrier slurry and process for high performance of ULK/Cu interconnects at the advacned technology node. Through balancing the removal rates of various films, the reasonable topography is obtained. Slurry formulation refinement and post-CMP treatment are applied together to recover k value and to improve within-die range under optimized process conditions. While the surface property and breakdown voltage of the metal layer have been studied, it’s found that post-polish cleaning in combination with CMP slurry plays a major role to enhance reliability.
Fullvision Endpoint Application on ILD0 P1 Polish
Authors: Zhang Han Xuan , Xu Ying , Zhao Run Tao
Published: March 2014

With continued scaling beyond 45 nm, endpointing is becoming essential for precise control of wafer-to-wafer and within-wafer uniformity during CMP processes. The Applied Materials FullVision™ endpoint system employs an in-line, large-spot, multi-wavelength light source (white light) and a spectrometer to collect spectral signals from the wafer while it is polishing. This makes possible a much more delicate and accurate control of endpoint triggering compared to the standard single-wavelength endpoint system. The FullVision system is beneficial for a variety of dielectric applications, including oxide, STI, and poly CMP. It has already been adopted by major memory customers and for BEOL copper inter-metal and top metal CMP on Applied Reflexion® LK CMP systems in high volume manufacturing. In this paper, we assessed the capability of FullVision to control the endpoint of a 28nm node ILD0 P1 polishing process on three kinds of patterned wafers with different masks. The results showed well-behaved linear fitting (> 0.98) of the endpoint traces of P1 polishing to the library data of a selected wafer, indicating that the FullVision system is qualified to moniter the ILD0 polishing process. Meanwhile, the endpoint times of tested wafers was controlled to within 25 seconds with the goodness-of-fit (GOF) value less than 2. These results demonstrated the capability of FullVision endpoint control for ILD0 P1 polish, indicating potential market growth for this system in 28nm CMP processes.
Laser Annealing Solution for FS-IGBT
Authors: Zhou Jiong , Wenren Qingqing , Meng Chunxia
Published: March 2014

Recent years, laser spike annealing (LSA) is considered to be mainstream technology for ultra-shallow junction (USJ), silicide formation and extended to insulated gate bipolar transistor (IGBT) annealing. Now, Shanghai Micro Electronics Equipment (SMEE) has achieved to find the solution for field stop IGBT (FS-IGBT) annealing. Comparing to traditional rapid thermal process (RTP), the advantages of LSA can be shown from several aspects. Firstly, I will introduce our laser annealing tool for FS-IGBT with its key specification overall and explain the consideration why FS-IGBT need LSA. Secondly, some experiment datum and predictable results have been analyzed and summarized in this article. Our work will continue to improve the tool performance by stability, repeatability and uniformity. Last but not least, we believed that laser spike annealing will become one of the key processes for FS-IGBT in the near future.
The Study of How to Reduce ILD Loss in High-k and Metal Gate Last Process
Authors: Zhao Jie , Gao Han Jie , Zeng Yi Zhi , Awut Kurban , Song Woei Ji , Yu Shao Feng , Cai Gorge , Zhang Bin
Published: March 2014

High-k last and metal gate last process becomes the main stream in 20nm and beyond technology. In high-k last process, the thermal dummy gate oxide (DGO) must be removed before the growth of interfacial layer (IL). In conventional process, to avoid the plasma damage to the device, wet etch is the most popular process to remove DGO. Because the etch rate of ILD(inter layer dielectric) oxide and CESL(CT etch stop layer) layers is much higher than thermal oxide, during the removal of DGO, serious ILD and CESL loss is observed, which will induce many of following process issues, such as high-k/metal residue, gate height variation, work function shift, etc. In this paper, multi-methods are studied to reduce the loss of ILD and CESL layer. The study mainly includes improvements on film quality and optimization of removal process. Finally, the selectivity of ILD oxide and CESL to thermal dummy gate oxide can reach ~1:1.
The Study of Low Moisture Molding Compound
Authors: Qiu Chi , Tan Wei , Liu Hongjie , Jiang Xiaojuan , Cheng Xingming , Han Jianglong
Published: March 2014

This paper studied the moisture of the post-mold-cured packages with the effects of resin structure, equivalent ratio of epoxy resin to Phenolic resin (E/OH), coupling agent, stress modifier and release agent on the moisture are further studied. The results showed that the resin structure has significant effect on the moisture, the order is multifunctional epoxy resin>o-crosel novolac epoxy resin>biphenyl epoxy resin>Naphthalene epoxy resin. The moisture decreases while the ration of E/OH increased. The moisture decreases rapidly with increase of the ratio of E/OH from 0.3 to 1.0. The moisture decreases slowly when it is larger than 1.0. The highest moisture of catalyst are 2MZ-A and 2MAOK while the lowest are 2MZ and TPP. The highest moisture of wax are GMS and stearic acid, while the lowest are polyethylene wax, oxidized polyethylene wax, and Carnauba wax, and the moisture of E wax, OP wax and S wax are in the middle.
A Novel Way of Controlling External Devices on DUT Board Synchronizing with the Test Sequencer
Authors: Hu Tianli
Published: March 2014

Advantest V93000 tester provides the utility lines to allow users to control the external devices on a DUT board, such as relays, EEPROMs, and indicators. Users can change the utility line setting by sending the dedicated firmware commands. However, because the sequencer breaks when the utility lines act, the test execution is interrupted and the test time increases considerately. To solve this issue, V93000 tester provides a new way to control utility lines without breaking the sequencer. Users can use utility lines to operate the external devices, synchronizing with the sequencer, at the cost of four additional digital pins. This paper introduces the concept of test sequencer synchronization. It also describes the process of switching and reading the utility line synchronizing with the sequencer. Finally the result is provided that the proposed procedure works effectively and the cost of test time is reduced greatly.
Novel Application in Laser Scanning (LS) Inspection for Advanced Logic Devices
Authors: Shan Chaojie , Yan Haibin , Peng Tingting , Zheng Yong , Biegas David , Chen Kan , Sun Shuo , Yin Jiajie , Wang Wenjie , Zhou Yun
Published: March 2014

Novel application of normal illumination during laser scanning (LS) inspection is presented in this paper, which can meet production requirements of both high throughput and good sensitivity at critical front-end-of-line (FEOL) - silicon-nitride removal (SIN-RM). As a complementary for conventional applications, this method has provided capture ability of ~30 nm protrusions/pattern fail for advanced logic devices, nuisance rate (NR) for inline inspection is around/below 30%. After inline performance monitor, this method can be applied for light starving layers and in-film defect detection, not only for better sensitivity, but also higher throughput compare with bright-field inspection. Higher sampling rate become practical for production inspection and more solid in-line data for faster yield improvement as a result.
The High Electron Dose of Voltage Contrast Inspection for the Detection of Nickel Silicide Piping Defects
Authors: Wang Kai , Chen Hunglin , Long Yin , Ni Qiliang , Fan Rongwei
Published: March 2014

Nickel silicide process is used for the ohmic contact formation, but it could be spiking or piping into the substrate and lead to the device fail by leakage with the high temperature anneal. The piping defect by the nickel silicide process was proposed to be inspected using the electron beam inspection (EBI) at contact tungsten (W) plug CMP. This paper aims at the methodology of piping defect inspection and presents an optimized method to detect true piping defects by high electrons dosage. In this study, The mechanism of the leakage spread effect is described and with a series of experiments during the recipe optimizeation, the electron dosage, landing energy and beam direction were identified to increase the piping defect capture rate.
Analysis of Intrinsic Retention Characteristics for 2x-Nm NAND Flash Memory Using TCAD Simulation
Authors: Lim Jun Yeong , Moon Pyung , Lee Sang Myung , Yun Ilgu
Published: March 2014

The retention characteristic of memory devices is an important issue as the size of the chip is scaled down continuously. However, it is hard to retain the reliable retention characteristic at smaller size of chip since the interference and leakage problems are induced by scaling down the chip. This paper suggests the main leakage mechanisms of 2x-nm flash memory at the pre-cycling situation by comparing the measurement Vth data with TCAD simulation to analyze this problem. Based on the results, we identify the failure mechanisms and factors which affect degradation of intrinsic retention characteristics.
Research on Multilevel Resistive Switching of Cu/HfO2/TiN Structure and Its Switching Mechanism
Authors: Wang Baolin , Zhang Kailiang , Wang Fang , Sun Kuo , Zhao Jinshi , Feng Yulin
Published: March 2014

In this paper, we have demonstrated multilevel resistive switching of Cu/HfO2/TiN structure in two methods. One method is to have different compliance currents during Set process and the other method is to implement various V
stop during Reset operation. 30 distinguishable switching cycles were achieved for each resistive switching states. At the same time, the switching mechanism of Cu/HfO2/TiN is analyzed. Low resistive state multilevel switching mechanism is ascribed to the intensity of metallic filaments. High resistive state multilevel switching mechanism is due to various V
stop resulting in different Schottky barrier heights.
High Performance Gallium Nitride GAA Nanowire with 7nm Diameter for Ultralow-Power Logic Applications
Authors: T V Anil Kumar , Chen Min-Cheng , Sheu Gene , Yang Shao-Ming
Published: March 2014

To increase typically low output drive currents from Si Nanowire field-effect transistors (FETs), we show a GaN based GAA Nanowire FET’s effectiveness. The theoretical study is focused on the three dimensional device designs, comparisons, random dopant fluctuation using IFM, and general variability issues including nanowire length, gate work function, and channel thickness are discussed. Performance of GaN GAA Nanowire is found to be increasing as Gate length is increased. Electrical characteristics of FETs including threshold voltage saturation, On/Off current ratio and sub threshold slope (SS) are analyzed. GaN GAA structure let to gate control ability improvement compared to Si based Nanowire in electrical performance. The GaN GAA Nanowire subthreshold slope is ~62mV/decade, which is close to the theoretical limit 60 mV/decade and leads to very high Ion/Ioff ratio of 1010-1011. The GaN GAA Nanowire is a very promising candidate for high-performance.
Dependence of Photoresponse Characteristics on I-Layer Doping for GaN Based P-I-N Ultraviolet Photodetectors
Authors: Wang Jun , Guo Jin , Xie Feng , Wang Guosheng , Wang Wanjun
Published: March 2014

We report on two-dimensional (2D) numerical simulations of photoresponse characteristics for GaN based p-i-n ultraviolet (UV) photodetectors. Effects of doping density of absorption layer (n

i
) on the photoresponse have been investigated. The Poisson and continuity equations are solved along each grid point in the 2D structure with three generation-recombination processes as Auger, Shockley-Read-Hall and optical generation-recombination. In order to accurately simulate the device performance, the theoretical calculation includes doping-dependent mobility degradation by Arora model and high field saturation model. Optimal doping concentration of absorption layers at different wavelength are extracted numerically. Theoretical modeling shows that the doping density of the absorption layer can significantly affect the photoresponse of GaN based p-i-n UV photodetectors.
RF Transmission Properties of Graphene with Coplanar Waveguide Structure
Authors: Zhang Liang , Wei Zijun , Jia Yuehui , Ren Liming , Shi Zujin , Fu Yunyi , Huang Ru , Zhang Xing
Published: March 2014

In this paper, we present the RF transmission characteristics of graphene-based coplanar waveguide (CPW) lines with different structure dimensions, including widths of signal trace, widths of ground plane, and spacings between the CPW signal and ground lines. It has been demonstrated that the energy loss of graphene-based CPW in the RF transmission process can be decreased by tuning the CPW dimensions. To further reduce the energy loss, both high-quality graphene and good contact between metal and graphene are required.
Machine Learning Based Lithography Hotspot Detection with Sparse Feature Encoding and Hierarchical Pattern Classification
Authors: Luo Kai sheng , Shi Zheng , Geng Zhen
Published: March 2014

Machine learning techniques have recently been applied to lithography hotspot detection. As an alternative to the accurate lithography simulation in early design stage, the ultimate objective of this methodology is to correctly detect hotspot patterns with high accuracy rate and fewer false alarms at a high speed. To better reach the above requirements, we propose a high performance lithography hotspot detection method based on Support Vector Machine (SVM) in this paper. A novel sparse feature encoding method based only on the vertices of the layout is used to transform the layout patterns in our algorithm. Hierarchical pattern classification method is used to reduce the false alarms recently, however, on the cost of hotspot detection accuracy rate. Modified hierarchical pattern classification architecture is proposed in this paper to address this drawback. We implement our algorithm under real manufacturing conditions and significant performance improvement is proved by experimental results.
Design of Integrated Four Quadrant Analog Multiplier
Authors: Li Wan , Jian Ren , Fuchao Li , Hui Xu
Published: March 2014

CMOS analog multiplier can be widely used in the filter, mixing or other signal processing circuits, as well as the control system of electronic circuit. This paper shows a design of one analog multiplier, using Gilbert unit as the main part. Our results show that, when the input voltage is between -4V and 4V, Vx and Vy exhibit excellent DC characteristic and well FM and AM characteristic. In addition, Frequency Doubling characteristic are good. Quiescent current is 2.16mA. Especially the value of THD in the same conditions compared to other design is lower. Circuit simulation, layout drawing and authentication software use Virtuso, Spectre, Caliber respectively which integrated in Cadence system. Final schematic and layout have passed DRC, LVS verification.
Effects of SiOx Barrier Layers Deposited by Spray Technique for CIGS Solar Cells on Metallic Substrates
Authors: Tseng Chien-Wei , Li Tomi T. , Lin Wei-Ting , Chen Sheng-Hui , Hu Sung-Cheng , Peng Wan-Hsuan , Lu Yung-Tien
Published: March 2014

In this study, SiOx layers were fabricated by spray pyrolysis deposition (SPD) and aerosol spraying as diffusion barriers between the stainless steel (SS) substrate (SUS430) and the molybdenum back contact layer in CuIn1-xGaxSe2 (CIGS) thin-film solar cells. SPD and aerosol spraying for SiOx layers are attractive processes for the deposition of thin films due to their low cost and controllable properties especially for solar cells on SS foils since a good barrier layer is required to prevent the Fe impurities (ions) defusing from SS substrate to the cells. The properties of SiOx barriers including thermal stability, microstructure content, electrical insulation and thickness of SiOx layers were investigated. The surface morphology and surface roughness were observed by scanning electron microscope and atomic force microscope. A transmission electron microscopy and X-ray diffractometer are adopted to measure the microstructural characteristics, grain size, and residual stresses of films. The chemical composition of the dielectric barriers was analyzed by X-ray photoelectron spectroscopy. The experimental results shows the specific thickness at 200 nm of SiOx layer will cause the absorber layer has the single chalcopyrite phase structure with (112) preferred orientation. The effects from the results revealed that the cells with a SiOx barrier layer fabricated by aerosol spraying provided a promising process in obtaining better CIGS cell performance.
Cortical Lewy Body Dementia
Authors: Gibb W. R. G.
Published: March 2014

In cortical Lewy body dementia the distribution of Lewy bodies in the nervous system follows that of Parkinson's disease, except for their greater profusion in the cerebral cortex. The cortical tangles and plaques of Alzheimer pathology are often present, the likely explanation being that Alzheimer pathology provokes dementia in many patients. Pure cortical Lewy body dementia without Alzheimer pathology is uncommon. The age of onset reflects that of Parkinson's disease, and clinical features, though not diagnostic, include aphasias, apraxias, agnosias, paranoid delusions and visual hallucinations. Parkinsonism may present before or after the dementia, and survival duration is approximately half that seen in Parkinson's disease without dementia.
Hyperlalia: A Right Cerebral Hemisphere Syndrome
Authors: Yamadori Atsushi , Osumi Yukio , Tabuchi Masayasu , Mori Etsuro , Yoshida Takashi , Ohkawa Shingo , Yoneda Yukihiro
Published: March 2014

We describe a new right hemispheric behavioural syndrome for which we propose the name “hyperlalia”. In a typical case an apparently unconcerned and expressionless patient is easily prompted to remarkable volubility with a content which is loose and incoherent. The voice is low and monotonous. All the lesions confirmed by computed tomography of the brain overlapped in the perisylvian area in the territory of the right middle cerebral artery. Loss of a subtle balance between the left hemispheric speech area and the corresponding area in the right hemisphere caused by acute damage of the right perisylvian area may have resulted in disinhibition of the speech function. Similarities and dissimilarities with the known pathology of talkativeness are also discussed.
Disconnection Syndrome and Verbal, Spatial and Tactile Amnesia following a Tumor of the Splenium of the Corpus Callosum
Authors: Scarpa Marina , Sorgato Paolo
Published: March 2014

A patient with a severe amnesic syndrome following a glioma of the splenium of the corpus callosum is reported. The long-term memory deficit involved anterograde as well as retrograde events dating back to 40 years and causing topographical disorientation. Short-term memory test performance was in the normal range, with the exception of tactile memory which was severely impaired. The patient also showed disconnection symptoms, due to severing of occipito-parietal and parieto-temporal connections, while parieto-parietal connections were undamaged.
Convulsive Pseudoseizures: A Review of Current Concepts
Authors: Savard Ghislaine , Andermann Frederick
Published: March 2014

Convulsive pseudoseizures thought to represent psychiatric disease can usually be detected early if they are considered in the epileptologist's differential diagnosis. No single diagnostic criterion for this behavioural disorder is known to be pathognomonic. Epilepsy and all physiological explanations have to be thoroughly ruled out and positive evidence of relevant psychopathology has to be gathered. The presence of pseudo seizures often heralds severe psychopathology, most frequently major affective disorder and major personality disorder, and occasionally, factitious disorder. Pseudoseizures can coexist with epileptic seizures and are often triggered by anticonvulsant toxicity. Diagnostic problems are more likely to be encountered in patients with frontal or parietal epilepsies, and in patients whose severe psychopathology is refractory to psychiatric intervention.
Oxcarbazepine in Monotherapy
Authors: Dam Mogens
Published: March 2014

Altogether 235 patients with newly diagnosed epilepsy were randomly allocated to treatment with either oxcarbazepine (OXC) or carbamazepine (CBZ) in a double-blind multicentre trial. After a titration phase of 4–8 weeks the optimum individual dose of trial medication was determined and treatment with this dose was continued for another 48 weeks. The results of the study indicate that there is no significant difference in seizure frequency between OXC and CBZ; no correlation was found between the therapeutic effect and EEG in either treatment group. OXC caused significantly (p = 0.04) fewer “severe” side-effects than CBZ. Global evaluation of tolerability showed a trend towards better tolerability of OXC. There way no correlation between either efficacy or tolerability and serum trough levels of the investigational drugs. Clinically relevant abnormal laboratory test findings were observed in two patients, both on CBZ. In conclusion, OXC is a major anti-epileptic drug, which is as effective as CBZ in the treatment of partial seizures and generalized convulsions. With fewer side-effects than CBZ, it represents a valuable alternative particularly in patients who develop side-effects which prevent optimum seizure control.
Fetal Growth, Gestation Length And Phosphoglucomutase‐1 Phenotype
Authors: Johnstone Frank D. , Westt John D. , Prescott Robin J. , Steel Judith M. , Flockhartt Jean A. , Greert Ian A. , Drago Guido A. , Whitehouse David B.
Published: March 2014

This study investigates reports that phosphoglucomutase‐1 (PGM1) phenotype is associated with fetal growth and gestation length. A total of 350 women were studied, 234 having uncomplicated pregnancies and 114 with a baby weighing greater than 90th centile, corrected for parity, gestation and fetal sex. All women had gestation confirmed by early ultrasound. Conventional cellulose acetate electrophoresis was used to distinguish the three common PGM1 phenotypes and polyacrylamide gel isoelectric focusing to distinguish the ten PGM1 SUbtypes. Neither PGM I phenotype nor SUbtype were found to be associated with gestation length or standardised birth weight. Logistic regression, where maternal age, parity, fetal sex, maternal weight, gestation and smoking were introduced as explanatory variables in addition to PGM1 phenotype testing against the dependent variables birth weight, standardised birth weight and gestation length, did not show differences related to PGM1 phenotype.

Two possible reasons for the discrepancy with previously published data are discussed. We conclude that the study provides no support for the belief that PGM1 phenotype is related to fetal growth or gestation length and that the original observations could have arisen as a result of statistical artefact due to multiple testing.