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61.
Adhesion studies of CVD copper metallization 总被引:2,自引:0,他引:2
Srinivas Gandikota Steve Voss Rong Tao Alain Duboust Dennis Cong Liang-Yuh Chen Sesh Ramaswami Daniel Carl 《Microelectronic Engineering》2000,50(1-4):547-553
The adhesion of chemical vapor deposition (CVD) Cu thin films to various barriers was observed to improve with a post-deposition anneal or a physical vapor deposition (PVD) Cu flash layer on the barrier before depositing CVD Cu. The ambient exposure of the barrier before the deposition of CVD Cu has been observed to lead to degradation of adhesion in both CVD Cu seed and CVD/PVD Cu high vacuum integrated metallization schemes. The integrated CVD and PVD Cu deposition scheme exhibits better adhesion due to the inherent annealing provided during the PVD deposition which is carried out at temperatures between 300 and 400°C. We have evaluated both qualitative and quantitative tests — tape test, Stud pull test and 4-point bend test — in understanding adhesion and observed that each of these tests give different details of interface breakdown. 相似文献
62.
Steve Jones 《世界电子元器件》2003,(7):44-46
运行在869MHz-2.17GHz频段内的蜂窝无线基站是射频功率晶体替如今最大的市场。其中,基中硅的LDMOS器件被广泛使用于500MHz=2.5GHz之间的射频功率放大器应用当中。作为增强模式的N沟道MOSFET,LDMOS器件(LD代表侧面扩散,描述了器件的沟道结构)专门被设计成为具有高的工作电压(长沟道)和低寄生电容,从而能在高频下工作。在早 相似文献
63.
Gregorio Martinez Perez Antonio F. Gomez Skarmeta Steve Zeber Joe Spagnolo Tim Symchych 《Communications Magazine, IEEE》2006,44(11):58-64
This article reports the latest results of an R&D effort to develop a prototype implementation of a dynamic policy-based network management (PBNM) system that can be used to configure and manage a secure network for a coalition environment across an unsecured wide area network. The prototype, based on a distributed architecture, includes capabilities for policy creation and management, dynamic policy negotiation, and dynamic policy provisioning. The policy negotiation facilitates the rapid deployment of a coalition network while the dynamic policy provisioning automates the configuration and management of network services including firewalls, virtual private network connections, routing, quality of service (QoS), and domain name services. Such a PBNM system enhances an organization's ability to react to network incidents identified by a network situational awareness assessment. Although the focus of the current research is a military coalition environment, the system can be used in any distributed enterprise or collaborative environment 相似文献
64.
Gunhyu Bae Yoo Sang Jeon Min Jun Ko Yuri Kim Seong-Beom Han Ramar Thangam Wonsik Kim Hee Joon Jung Sungkyu Lee Hyojun Choi Sunhong Min Hyunsik Hong Sangwoo Park Seong Yeol Kim Kapil D. Patel Na Li Jeong Eun Shin Bum Chul Park Hyeon Su Park Jun Hwan Moon Yu Jin Kim Uday Kumar Sukumar Jae-Jun Song Soo Young Kim Seung-Ho Yu Yun Chan Kang Steve Park Seung Min Han Dong-Hwee Kim Ki-Bum Lee Qiang Wei Liming Bian Ramasamy Paulmurugan Young Keun Kim Heemin Kang 《Advanced functional materials》2021,31(37):2103409
Developing materials with the capability of changing their innate features can help to unravel direct interactions between cells and ligand-displaying features. This study demonstrates the grafting of magnetic nanohelices displaying cell-adhesive Arg-Gly-Asp (RGD) ligand partly to a material surface. These enable nanoscale control of rapid winding (“W”) and unwinding (“UW”) of their nongrafted portion, such as directional changes in nanohelix unwinding (lower, middle, and upper directions) by changing the position of a permanent magnet while keeping the ligand-conjugated nanohelix surface area constant. The unwinding (“UW”) setting cytocompatibility facilitates direct integrin recruitment onto the ligand-conjugated nanohelix to mediate the development of paxillin adhesion assemblies of macrophages that stimulate M2 polarization using glass and silicon substrates for in vitro and in vivo settings, respectively, at a single cell level. Real time and in vivo imaging are demonstrated that nanohelices exhibit reversible unwinding, winding, and unwinding settings, which modulate time-resolved adhesion and polarization of macrophages. It is envisaged that this remote, reversible, and cytocompatible control can help to elucidate molecular-level cell–material interactions that modulate regenerative/anti-inflammatory immune responses to implants. 相似文献
65.
Davidson BS Madigan ML Southward SC Nussbaum MA 《IEEE transactions on bio-medical engineering》2011,58(6):1546-1554
This study investigated the effects of aging and localized muscle fatigue on the neural control of upright stance during small postural perturbations. Sixteen young (aged 18-24 years) and 16 older (aged 55-74 years) participants were exposed to small magnitude, anteriorly-directed postural perturbations before and after fatiguing exercises (lumbar extensors and ankle plantar flexors). A single degree of freedom model of the human body was used to simulate recovery kinematics following the perturbations. Central to the model was a simulated neural controller that multiplied time-delayed kinematics by invariant feedback gains. Feedback gains and time delay were optimized for each participant based on measured kinematics, and a novel delay margin analysis was performed to assess system robustness. A 10.9% longer effective time delay ( p = 0.010) was found among the older group, who also showed a greater reliance upon velocity feedback information (31.1% higher differential gain, p = 0.001) to control upright stance. Based on delay margins, older participants adopted a more robust control scheme to accommodate the small perturbations, potentially compensating for longer time delays or degraded sensory feedback. No fatigue-induced changes in neural controller gains, time delay, or delay margin were found in either age group, indicating that integration of this feedback information was not altered by muscle fatigue. The sensitivity of this approach to changes with fatigue may have been limited by model simplifications. 相似文献
66.
Private mobile radio (PMR) services are widely used in business and emergency applications. Typically, these services use the UHF 2 band (450–470 MHz). In order to comply with continental practice, the provision of these services in the UK is to be realigned and a new operational assignment will be generated in 2005. However, this can only be achieved with an appropriate model and the ability to make assignments for large regional networks. The purpose of this paper is to bring our experiences of this problem to the wireless arena. We explain the model used when making assignments for UK PMR networks and identify existing techniques and theory which are appropriate for this problem. We demonstrate that improved assignments and estimates of spectral requirements for large operational services can be found. 相似文献
67.
汽车信息娱乐系统(见图1)时代的到来标志着汽车采甩简单车载收音机(如图2中Mercedes汽车所配备的仪表板)的日子一去不复返了。历史悠久的AM/FM收音机在信息娱乐控制板上仍然保有一席之地,但它与数字音频广播(DAB)、数字和高清晰度电视(HDTV)、卫星无线电、集成蜂窝电话、CD/DVD/MP3播放器、全球定位系统(GPS)导航及视频游戏系统组合在一起。 相似文献
68.
Silicide-block-film effects on drain-extended MOS (DEMOS) transistors were comparatively investigated, by means of different film stack stoichiometric SiO2 and silicon-rich oxide (SRO). The electrical properties of the as-deposited films were evaluated by extracting source/drain series resistance. It was found that the block film plays a role like a field plate, which has significant influence on the electric field beneath. Similar to hot-carrier- injection (HCI) induced degradation for devices, the block film initially charged in fabrication process also strongly affects the device characteristics and limits the safe operating area. 相似文献
69.
Faced with the world’s largest Internet population, the Chinese government is torn between its massive drive for marketization and the need to curb cyber dissent. This paper investigates how the Chinese state censors the Internet by tracing the trajectory of mechanisms to block websites non grata. Results show that Chinese government’s Internet control methods are diverse with systematic collaborations from local authorities at various administrative levels. We also found evidence that the government has customized blocking strategies for what it considers to be important websites. The efficacy and implications of China’s Internet censorship system were also discussed. 相似文献
70.
数字版权管理(DRM)与内容保护需要运用特别的通讯协议,在微软的DRM引擎Janus中,底层采用的技术为MTP.MTP可被视为取代传统MSC的方案,能传送受保护的内容.图1是传统海量存储装置应用以及相关的软件堆栈. 相似文献